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Failed CA smog twice need advice

8K views 35 replies 21 participants last post by  Locruid 
#1 · (Edited)
Hi my 97tj failed smog twice.what I've done so far.
New rotor/cap, plugs/wires, oil change and engine flush,new 02 sensors,new cat.timing was checked and that's fine too..I did take it to smog station within 10 mins of cat replacement would this cause a fail?out of ideas and money lol. :(
1st test it failed for ppm at 15mph
Max 539 Ave 103 meas 1074
Barely passed ppm at 25mph
Max 792 Ave 95 meas 766
Some reason pic from 1st test didn't load.

Pic is of 2nd test..
Ppm did drop some..so was it because I didn't
let cat break in or something else?
Any help or advice would make my day!! :)
 

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#3 ·
I did take it to smog station within 10 mins of cat replacement would this cause a fail?
Cats need to be very hot in order to work well. I doubt that a ten minute putt over to the smog testing station would get the cat hot enough. I'd suggest going for a longer drive and don't let the Jeep cool off before the test. I've failed a smog test on another vehicle and the tech had me go for a drive and come back and go straight into the test. The vehicle passed.
 
#6 ·
Thanks for the advice..I figured I went to soon..I'm going break cat in for few more days and try again..is there a product i could add to the fuel to help?
I don't think there is any break-in with cats. Just make sure you drive for a while (don't use the temp gauge as an indication of the temp of the cat). I doubt the effectiveness of the "guaranteed to pass" type of fuel additives.
 
#5 ·
Moving is out of the question, I assume?

There's no "magic bullet" but a quick search turned this up: asphaltene conditioner
What Fuel Additives Lower Emission - Ask.com

A broad spectrum analysis may show certain additives were used, versus a simple sniffer - not sure.

A hot cat will make a difference over a cold one - much of the pollution on modern cars comes from the "warm up " period these days.
 
#7 ·
What cats did you put in?

California emissions are much much stricter then any other state so the quality of your cats matters A LOT. Most cats I see on sale are only 49 state legal, meaning if your in california you will fail emissions with their cat.
 
#12 ·
First, is the correct 195 degree model thermostat installed? Running a 165 or 180 degree thermostat can cause the engine to run too cool to pass the test. And as said above, the catalytic converter has to be hot which means the engine must be fully warmed up. A short drive before the smog test is not usually enough.
 
#16 ·
Ok, if you have not cleared the lkast test record from your vehicle memory, do so with your scan tool. ( Autozone,pepboys,etc), then run your vehicle for the 20 minutes reccommended, and retest. Also, check your gas cap for tight, your temp for up to snuff, and run some good fuel when you tank up next. Good luck on this, as I had the same problem, which turned out to be a bad gas cap, and parking on an incline overnite! Yeah, the cap was getting fuel in the vent, and then the purge was not clearing it out.
 
#20 ·
On your TJ you probably have the Two way CAT. Which not meant to reduce NO emission. Gasoline engine should not produce high NO emission at all. If your engine running temp is normal (I would assume so base on all other emissions). My guess will be you are burning oil.
 
#24 ·
OP ... make sure the test is performed properly.

The tech must heat the cat(s) by running the engine at a high RPM (2,500) for approx 2-3 min. California keeps changing the threshold... however my 1991 XJ has a smog test result of a new Honda Accord.

Make sure you are not getting a false reading from a hidden crack in the factory exhaust header - known issue.

.
 
#25 ·
Doesn't have an egr valve but the tech found a leak where the egr would hook up..there's a small plate there with a gasket that is leaking and failing me..new problem is they cannot locate a replacement gasket lol..he's trying to fabricate 1 now..even the jeep dismantler doesn't have the stupid gasket :(
 
#26 ·
If the EGR leak is in the intake manifold just make a gasket out of high temp RTV and cut out piece of beer can. To pass emissions just empty your gas tank of gas and refill with 1 gallon mixture 50/50 mixture of ethanol and toluene. Works every time. After test just fill it the rest of the way up with gasoline.
 
#28 ·
My suggestion wont help you pass a SMOG test, but if in the future it is accomplished, it wont matter. My suggestion is to start a petition to "De-Fund, and Repeal, the California Air Resources Board's, (CARB) charter, and fire all of their "Marxist," bureaucrats! What Say You?
 
#30 ·
Here's what me and my buddies did when we had a vehicle that wouldn't smog in Ca (mind you we were stationed in the central valley with A LOT of shady people)

Go to a small smog shop off the beaten path. Fail. Slip the guy an extra $50-75. Pass. Then if you're genuinely concerned about fixing your emissions problem you have now bought yourself plenty of time.
 
#31 ·
The smog laws here are really harsh..if I didn't love California so much I would move..I've lived in Texas and Alabama..but this is home..I still have a small exhaust leak somewhere..But the tech still passed me so 2 years to trace down the problem..some here think a small leak is a non issue but having the main leak fixed yesterday increased my horsepower and my 97tj runs like its new again...I really am thankful for this community :)
 
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