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Topic Review (Newest First)
06-28-2014 08:32 AM
Digger84 Nice photo but the last cat I saw de bricked was an 84 z31 turbo and all that was inside was one honeycomb brick at least till it was broken out and removed

Pretty mid 80s and not near that complex
Car did also have egr

Based on what you say any tj as they all have OBD 2 and simple voltage generating o2 sensors 2 or 4 of them depending on the year has no worries on oxides of nitrogen in the free states as the only smog check is obd2 link up so no oxide of nitrogen sensor involved

Only the poor slubs in the 74 to 95 range get the tail pipe sniffer out here
06-27-2014 10:28 PM
2xs
Quote:
Originally Posted by snore View Post
Sorry about that, didnt even look at it to see that you could not read it. I'll try again. I'm going to drive it longer when I take it back. I kind of wish I went to my regular smog guy but this one was cheaper.




Aww I was hoping to just weld it. Oh well looks like I am in the market for a new header. Any suggestions anyone??
I have welded many, its the CAST ones you cant weld....
06-27-2014 10:19 PM
snore
Quote:
Originally Posted by 2xs View Post
NP, lol





The actual procedure is to let it run at idle for 3 minutes after it is fully warmed up.
If the tech is lazy, he will test it however it comes in not paying any attention to temp.
If I remember EO632678 ( STAR Inspector Page ) had no score before Jul 2012, telling me he is sorta a new tech, and prone to "forgetting" basic procedure.

Take it for a long drive and dont shut it off when you take it in.

However 14.? and 15% CO2 show me GOOD efficiency, so I usually gravitite to exhaust leak before the cat, or weak junk cat if all the numbers are high.

Next time scan the report, I cant read the numbers on your current image.

Also, ref:
Vehicle Test History
Sorry about that, didnt even look at it to see that you could not read it. I'll try again. I'm going to drive it longer when I take it back. I kind of wish I went to my regular smog guy but this one was cheaper.


Quote:
the older cars are not as "spot on" as the OBDII systems, so it takes longer to "get into efficiency".

I always tell my customers, fire up your car, take a 15 minute drive, maybe go a mile or two at freeway speed, roll up to the smog stall and DO NOT SHUT IT OFF... these cats have to fire up to 900-1100 degrees before they start cleaning, and in an older OBDI it takes longer for it to all heat up, your cat is probably weak, but that doesn't mean it needs to be replaced just yet

THAT HAIRLINE CRACK will be the big problem.... it pulses every time a cylinder fires and puffs in alittle oxygen from the outside... when this happens the extra o2 renders the cat useless, you can weld the crack up....its going to crack again probably before you get to the smog bay.

I had a hairline crack in my header and was blowing 1500 at 15mph and 2130 at 25.....threw on a header THINKING FOR SURE I was going to need a cat... that sucker went down to under a hundred either speed.
Aww I was hoping to just weld it. Oh well looks like I am in the market for a new header. Any suggestions anyone??
06-27-2014 10:10 PM
2xs
Quote:
Originally Posted by Digger84 View Post
First it does not rip anything a catylist just like carbonic anhydride in your body lowers the activation energy for the reaction

Next you think 80s cats had more the one brick of catalyst inside well I guess you never looked inside

The did have egr to cool and reduce formation icy des of nitrogen
Rip is the word I chose for the action of the catalyst separating the N from the NO or NO2 molecules, I used that word so the untrained can understand..

80's cats had 2 beds, top and bottom, same idea, different (less efficient) approach.
See the little louvers int he top of the plate in the middle of the attached pic of an '80s cat? they only lead fresh air to the upper portion of the cat to reduce HC and CO...

Quote:
icy des of nitrogen
Heh, you mean Oxides of Nitrogen? NOx?
06-27-2014 09:33 PM
Digger84 First it does not rip anything a catylist just like carbonic anhydride in your body lowers the activation energy for the reaction

Next you think 80s cats had more the one brick of catalyst inside well I guess you never looked inside

The did have egr to cool and reduce formation icy des of nitrogen

Early 70s no cats at all just good old leaded fuel which was a cat coaster/ killer

Do miss lots about 70
R12
Cheap high octane gas
Not ashamed of American exceptional ism
And just proposing to use IRS against political enemies or loosing two minutes of a recorded conservation ended a presidency
US and only US made several trips to the moon
Just a few reasons I miss the70s
06-27-2014 09:01 PM
2xs
Quote:
Originally Posted by Digger84 View Post
I don't see how letting the cat have extra o2 would make it not work but it will play hell with ant down stream o2 sensor and cause the PCM to run injectors rich


If extra o2 made cat not work all those air injector pumps would have killed cats

One function of a cat is to finish burning ie oxygenating any incompletely burnt hydrocarbons you want to fully oxygenate to the end products of co2 and h2o
Do you have ANY idea how a modern cat works?
you seem stuck in the '70s...

Quote:
Most modern cars are equipped with three-way catalytic converters. This refers to the three regulated emissions it helps to reduce.
The reduction catalyst is the first stage of the catalytic converter. It uses platinum and rhodium to help reduce the NOx emissions. When an NO or NO2 molecule contacts the catalyst, the catalyst rips the nitrogen atom out of the molecule and holds on to it, freeing the oxygen in the form of O2. The nitrogen atoms bond with other nitrogen atoms that are also stuck to the catalyst, forming N2. For example:
2NO => N2 + O2 or 2NO2 => N2 + 2O2
2NO => N2 + O2 or 2NO2 => N2 + 2O2

Ceramic honeycomb catalyst structure.
The oxidation catalyst is the second stage of the catalytic converter. It reduces the unburned hydrocarbons and carbon monoxide by burning (oxidizing) them over a platinum and palladium catalyst. This catalyst aids the reaction of the CO and hydrocarbons with the remaining oxygen in the exhaust gas. For example:
2CO + O2 => 2CO2
Ref: HowStuffWorks "Catalysts"

now when we flood the front half of the cat (the reduction catalyst) with O2 from an exhaust leak, it stops the platinum and rhodium from being able to split the O from the NO or NO2 molecule.
This is why we ALWAYS hammer people to verify there is no exhaust leaks before the cat, not only does it leak exhaust OUT, but it lets AIR IN (think pulse air injection).
You will notice most JEEP air injection systems are pulse systems, one at the manifold, to help warm the exhaust and fire off the cat, and one in the MIDDLE of the cat AFTER the reduction catalyst portion of the cat.

The air the pulse air injection system injects helps the rear half of the cat (The oxidation catalyst) finish off the burning of the HC and CO left in the exhaust that did not burn during normal combustion. It is plumed into the center of the cat intentionally so it does not flood the reduction bed with AIR, reducing or killing its ability to reduce NOx.

The O split from the NO or NO2 molecules from the reduction bed (front half) is used in the rear half of the cat to better burn the CO and HC, this si so efficient it sometimes allows the complete removal of the air injection system at the factory, and is incorporated in modern emissions design on most newer vehicles.
06-27-2014 08:28 PM
redneckbrat Just to be clear about Seafoam and my story, it was with my old cat not my new one. At this point if I were to use Seafoam again it would only go in the gas tank. I just got some Lucas Oil, we'll see what happens with that.
06-27-2014 08:06 PM
bangingears
Quote:
Originally Posted by Digger84 View Post
I don't see how letting the cat have extra o2 would make it not work but it will play hell with ant down stream o2 sensor and cause the PCM to run injectors rich


If extra o2 made cat not work all those air injector pumps would have killed cats

One function of a cat is to finish burning ie oxygenating any incompletely burnt hydrocarbons you want to fully oxygenate to the end products of co2 and h2o
it is a balancing act.... so much o2 in a cat will clean up so much Nox... to much 02 and the cat wont clean up the nox, most of the injection pump vehicles where carbed or crappy FI systems, you had an over abundance of raw fuel entering the cat with a lack of oxygen, you pumped AIR INTO THE CAT, to build heat and burn the mixture. Thats all a cat does is store oxygen and release it at a calulated rate... to much oxygen and it wont clean up the bi-products it's trying to work on. I was kinda surprised air injection made it all the way up to the LS motors on some early 5.3's.
06-27-2014 07:52 PM
Digger84 I don't see how letting the cat have extra o2 would make it not work but it will play hell with ant down stream o2 sensor and cause the PCM to run injectors rich


If extra o2 made cat not work all those air injector pumps would have killed cats

One function of a cat is to finish burning ie oxygenating any incompletely burnt hydrocarbons you want to fully oxygenate to the end products of co2 and h2o
06-27-2014 07:09 PM
2xs
Quote:
Originally Posted by bangingears View Post
ooo 2xs i wasnt trying to step on your toes, just putting my .02 in...

my other credit is, "i am a random dude on an internet not necessarily wearing clothes at the moment".

just seems in the last 6 months every jeep that has come in the guy immediately says "i sea foamed it" with a giant grin, and it's like... well go drive a few tanks through it cause if your jeep looks like a mosquito fogger just imagine the bigger chunks that haven't made it through....

I was more or less saying to Brat, stop throwing new things on the rig, start playing with your system as it is...fix it... then start with new things. I personally have not thrown injectors on my jeep, but just seeing what some of the mustangs, sbc and other obdI cars I have dealt with, increasing the injector size only makes the computer lean out the pulse width. I do know on the YJ's you can fool the MAF sensor and it will think its getting more are then it should and i have heard of guys with 4.6-4.7's doing that so the engine will actually use the LB rating of the injector.
NP, lol

Quote:
Originally Posted by snore View Post
yes I did shut it off before the test. Think my cat was not hot enough? It was a short drive there, and now that I think about it, it was shut off and started 3 times before starting the test. (not sure if that makes a huge difference) I was under it today and I think I have a hairline crack in one of the pipes going down right where it goes into one pipe.


The actual procedure is to let it run at idle for 3 minutes after it is fully warmed up.
If the tech is lazy, he will test it however it comes in not paying any attention to temp.
If I remember EO632678 ( http://www.smogcheck.ca.gov/pubwebqu...px?tech=632678 ) had no score before Jul 2012, telling me he is sorta a new tech, and prone to "forgetting" basic procedure.

Take it for a long drive and dont shut it off when you take it in.

However 14.? and 15% CO2 show me GOOD efficiency, so I usually gravitite to exhaust leak before the cat, or weak junk cat if all the numbers are high.

Next time scan the report, I cant read the numbers on your current image.

Also, ref:
http://www.smogcheck.ca.gov/pubwebqu...PubTstQry.aspx
06-27-2014 07:06 PM
bangingears
Quote:
Originally Posted by snore View Post
yes I did shut it off before the test. Think my cat was not hot enough? It was a short drive there, and now that I think about it, it was shut off and started 3 times before starting the test. (not sure if that makes a huge difference) I was under it today and I think I have a hairline crack in one of the pipes going down right where it goes into one pipe.
the older cars are not as "spot on" as the OBDII systems, so it takes longer to "get into efficiency".

I always tell my customers, fire up your car, take a 15 minute drive, maybe go a mile or two at freeway speed, roll up to the smog stall and DO NOT SHUT IT OFF... these cats have to fire up to 900-1100 degrees before they start cleaning, and in an older OBDI it takes longer for it to all heat up, your cat is probably weak, but that doesn't mean it needs to be replaced just yet

THAT HAIRLINE CRACK will be the big problem.... it pulses every time a cylinder fires and puffs in alittle oxygen from the outside... when this happens the extra o2 renders the cat useless, you can weld the crack up....its going to crack again probably before you get to the smog bay.

I had a hairline crack in my header and was blowing 1500 at 15mph and 2130 at 25.....threw on a header THINKING FOR SURE I was going to need a cat... that sucker went down to under a hundred either speed.
06-27-2014 07:05 PM
snore
Quote:
Originally Posted by redneckbrat View Post
OK, I have an 02 sensor that is about a yr old, got off of ebay, new, only paid about $15. I saw somewhere in this thread I think to stay away from the Bosch 02's. The place that tested it last is a Star and CAPS station. That's why I went to them. I also had them do a diagnostic and they found no leaks, or other issues other than NOx being too high. Bangingears, where are you at? I'd like to come to either you or 2xs, but don't really want to drive an hour and half to get there. I'm in Sacramento.

I'm headed out shortly and will get some marvel mystery oil. I wish I has seen this before getting gas yesterday. I have to do some driving and then switch to premium for a couple of tanks.
lol I was thinking the same thing I just filled my tank with regular.
06-27-2014 07:01 PM
redneckbrat OK, I have an 02 sensor that is about a yr old, got off of ebay, new, only paid about $15. I saw somewhere in this thread I think to stay away from the Bosch 02's. The place that tested it last is a Star and CAPS station. That's why I went to them. I also had them do a diagnostic and they found no leaks, or other issues other than NOx being too high. Bangingears, where are you at? I'd like to come to either you or 2xs, but don't really want to drive an hour and half to get there. I'm in Sacramento.

I'm headed out shortly and will get some marvel mystery oil. I wish I has seen this before getting gas yesterday. I have to do some driving and then switch to premium for a couple of tanks.
06-27-2014 06:30 PM
snore
Quote:
Originally Posted by bangingears View Post
Take it for Wat it is worth but I work at a star certified smog facility and I am caps certified, I deal with 30-40 smog failures a year and we have a huge jeep base

Snore do not buy a cat or an o2 did u shut your vehicle off before the test? It looks like your cat Never lit off

Brat, you have a exhaust leak somewhere, your injectors are fine, throwing larger ones in will only make your computer lean the pulse out and in turn build more heat.

For heavens sake stop throwing sea foam at the rigs! Sea foam kills cats more than any other product on the market. When u take all that crap out so quickly all it does is sit in front of the cat or bakes itself into it and cause even worse performance.

Use Lucas fuel additive, startron or 44k.

Also nox can be through the roof because of plugged fuel filters, these are obd I cars so it won't throw a code for something's. Poor fuel regulators can do the same thing

02 sensors are tricky our computers switch slowly the o2sof today switch super fast so more often then not on the obd 1 jeeps they actually lean out and raise the nox. The only one that works well is the factory dealer ones but I refuse to pay 200 bucks for an o2 when I can get better results from another area.

Always run 91 or higher in the rig for a smog, the 4.0s are tuned lean on purpose and 87 burns a good 100-150 hotter in jeeps I have found this through 4 jeeps. I have played on the Dyno I have seen it myself.

Also dumbing a 12 ozof marvel mystery oil does majgic for injectors and burning the carbon off valve stems and the back of the valve.

Good luck
yes I did shut it off before the test. Think my cat was not hot enough? It was a short drive there, and now that I think about it, it was shut off and started 3 times before starting the test. (not sure if that makes a huge difference) I was under it today and I think I have a hairline crack in one of the pipes going down right where it goes into one pipe.
06-27-2014 05:13 PM
bangingears ooo 2xs i wasnt trying to step on your toes, just putting my .02 in...

my other credit is, "i am a random dude on an internet not necessarily wearing clothes at the moment".

just seems in the last 6 months every jeep that has come in the guy immediately says "i sea foamed it" with a giant grin, and it's like... well go drive a few tanks through it cause if your jeep looks like a mosquito fogger just imagine the bigger chunks that haven't made it through....

I was more or less saying to Brat, stop throwing new things on the rig, start playing with your system as it is...fix it... then start with new things. I personally have not thrown injectors on my jeep, but just seeing what some of the mustangs, sbc and other obdI cars I have dealt with, increasing the injector size only makes the computer lean out the pulse width. I do know on the YJ's you can fool the MAF sensor and it will think its getting more are then it should and i have heard of guys with 4.6-4.7's doing that so the engine will actually use the LB rating of the injector.
06-27-2014 02:14 AM
2xs
Quote:
Originally Posted by bangingears View Post
Brat, you have a exhaust leak somewhere, your injectors are fine, throwing larger ones in will only make your computer lean the pulse out and in turn build more heat.
Only reason im doing injectors on my '93 is for the spray pattern, better atomization has loads of benefits.
Including a more consistent burn, with the potential to lower NOx.
Ordering an O2 from Quadratech (OE type, $62.)

FYI: Im a Star Smog tech as well, Been doing this since '93...
At a Test only shop now (I manage 2 stores), with a .99 (seriously).
http://www.smogcheck.ca.gov/pubwebqu...px?tech=132430
06-27-2014 02:02 AM
bangingears Take it for Wat it is worth but I work at a star certified smog facility and I am caps certified, I deal with 30-40 smog failures a year and we have a huge jeep base

Snore do not buy a cat or an o2 did u shut your vehicle off before the test? It looks like your cat Never lit off

Brat, you have a exhaust leak somewhere, your injectors are fine, throwing larger ones in will only make your computer lean the pulse out and in turn build more heat.

For heavens sake stop throwing sea foam at the rigs! Sea foam kills cats more than any other product on the market. When u take all that crap out so quickly all it does is sit in front of the cat or bakes itself into it and cause even worse performance.

Use Lucas fuel additive, startron or 44k.

Also nox can be through the roof because of plugged fuel filters, these are obd I cars so it won't throw a code for something's. Poor fuel regulators can do the same thing

02 sensors are tricky our computers switch slowly the o2sof today switch super fast so more often then not on the obd 1 jeeps they actually lean out and raise the nox. The only one that works well is the factory dealer ones but I refuse to pay 200 bucks for an o2 when I can get better results from another area.

Always run 91 or higher in the rig for a smog, the 4.0s are tuned lean on purpose and 87 burns a good 100-150 hotter in jeeps I have found this through 4 jeeps. I have played on the Dyno I have seen it myself.

Also dumbing a 12 ozof marvel mystery oil does majgic for injectors and burning the carbon off valve stems and the back of the valve.

Good luck
06-27-2014 12:37 AM
2xs
Quote:
Originally Posted by redneckbrat View Post
2Xs, what year Mustang injectors are you using?
The ones I got came out of a 1995 4.6L Mercury
They look yellow, but they are orange.
I might return them and grab 6 Neon injectors tho....
06-26-2014 10:49 PM
redneckbrat
Quote:
Originally Posted by snore View Post
Thanks for the tips. So you took the Tstat completely out? I've changed the plugs ill have to change the rest of It though. I just need to do all I can I get a free retest within30 days.
Yes, I took it completely out. Not sure if that truly helped or not. It certainly runs a lot cooler.


2Xs, what year Mustang injectors are you using?
06-26-2014 06:25 AM
Digger84 Platinum and palladium inside cats does not come cheap
06-25-2014 10:27 PM
2xs yup...
06-25-2014 10:07 PM
snore
Quote:
Originally Posted by 2xs View Post
Top engine clean and an O2 sensor, leave the cat alone for now.
He is kinda a new tech, so take what he says with a grain of salt...

Also, MAKE SURE there are NO cracks in the manifold, and NO LEAKS in the exhaust before the cat, that will disable the front half of the cat, which is where the NOx reduction portion of the cat is...

STAR Inspector Page
Thanks. So when you say top engine clean is that using seafoam through a vacuum line. I think you described earlier in this thread? This is where I'm going to start because I didn't realize cats were flippin expensive lol.
06-25-2014 09:50 PM
2xs
Quote:
Originally Posted by snore View Post
My 91 just failed smog too. The tech said to change the cat and oxygen sensor. Any other suggestions to get this thing to pass? Thanks.
Top engine clean and an O2 sensor, leave the cat alone for now.
He is kinda a new tech, so take what he says with a grain of salt...

Also, MAKE SURE there are NO cracks in the manifold, and NO LEAKS in the exhaust before the cat, that will disable the front half of the cat, which is where the NOx reduction portion of the cat is...

STAR Inspector Page
06-25-2014 08:28 PM
snore
Quote:
Originally Posted by redneckbrat View Post
from what you posted, you're running lean like me, not as bad tho. do a tune up, plugs, wires, cap/rotor. I took my t-stat out, it helped. From your numbers, that might be all you need to do. From what everyone is saying, if you are running lean, you are running hot. When I took my t-stat out, my NOx when from 1200's to 1000's. Dropped nearly 200 pts.
Thanks for the tips. So you took the Tstat completely out? I've changed the plugs ill have to change the rest of It though. I just need to do all I can I get a free retest within30 days.
06-25-2014 07:54 PM
Digger84 The green weenies in calif want all older less green vehicles off the roads either confirm with governor moonbeam and his minions or leave the people's republic of calif

You will feel much more free in a less solicit state
06-25-2014 07:52 PM
redneckbrat from what you posted, you're running lean like me, not as bad tho. do a tune up, plugs, wires, cap/rotor. I took my t-stat out, it helped. From your numbers, that might be all you need to do. From what everyone is saying, if you are running lean, you are running hot. When I took my t-stat out, my NOx when from 1200's to 1000's. Dropped nearly 200 pts.
06-25-2014 07:48 PM
snore My 91 just failed smog too. The tech said to change the cat and oxygen sensor. Any other suggestions to get this thing to pass? Thanks.
06-21-2014 09:12 PM
redneckbrat
Quote:
Originally Posted by Digger84 View Post
Could be the angle of pic but gaps look very inconsistent especially last two photos
it is the angle. they all looked about the same.
06-21-2014 07:01 AM
Digger84 Could be the angle of pic but gaps look very inconsistent especially last two photos
06-21-2014 12:44 AM
2xs
Quote:
MMT Fouled
APPEARANCE: Spark plugs fouled by MMT (Methycyclopentadienyl Manganese Tricarbonyl) have reddish, rusty appearance on the insulator and side electrode.

CAUSE: MMT is an anti-knock additive in gasoline used to replace lead. During the combustion process, the MMT leaves a reddish deposit on the insulator and side electrode.

RECOMMENDATION: No engine malfunction is indicated and the deposits will not affect plug performance any more than lead deposits (see Ash Deposits). MMT fouled plugs can be cleaned, re-gapped and re-installed.
Lost the source, but otherwise it looks ok... a tad burnt (not melted) ont eh electrode, which could point to heat, but meh...
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