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Topic Review (Newest First)
12-03-2014 11:08 AM
djlash
02 jeep

i have a 02 wramgler 2.5. i just had a head issue and took the head off and had it tested. shop told me no cracks just warped bad. had it surfaced and put it back on, by the way the engine got hot to cause this problem. now it does not return to idle right and runs rough, also once in awhile it will pop back through the carb. anyone have help? also now just got a 455 code
04-29-2014 12:59 AM
Spook
A two dollar smoke machine?

Would using a cigar work for a smoke machine?

By the way, what's up with the $100 locking gas cap that has to be keyed to the ignition?
02-25-2014 08:36 PM
Bburton I have been battling code also.
I have replaced hoses, added clamps.
Fuel cap, vent solenoid, leak detection pump because mine was busted will attach pic of it. Still have code, have traced lines back to tank. Have felt for corrosion on fuel filler and tightened up vac lines and fuel hose on tank. Today I ran codes and p0455 was back again.

Attachment 808585
01-11-2014 11:11 AM
4xWheeler I Had the same codes and found two hard lines that ran from the fuel tank, along the frame on the drivers side then up toward the motor by the drivers side. They had rubber hoses as an elbow which passed by the two cats coming off the exhaust. They were dry rotted, probably from the heat coming from the cats, as seen in the prior pics on this post. I had to look from under the vehicle to find them though.
01-11-2014 10:13 AM
Bubs I have same problem in my 01 tj sport. I have a stant locking gas cap but also my hoses are dry rotted. I am going to replace gas cap with oem cap because the lock on mine was always funky. I am going to check to see if that solved it, but I am getting hoses too and retest. I think mine are definitely hoses, but I am going to try one at a time and see if code p0455 goes away.
04-28-2013 07:29 PM
JellisTJ I just got that code the other day and fixed some hoses going to and from my evap canister. I was confused at first what it was because I don't remember it on my '00.
.
04-26-2013 01:58 PM
d6cat I have the leak detection pump off to check it. If I apply vacuum to the diaphram side of the electrical switch should it close the valve so that no air will pass through where the 2 large hoses connect? Air passes through whether there is vacuum applied or not. It seems like the passage should close one way or the other. Am I wrong?
04-25-2013 02:45 PM
workshop4ever I just bought my jeep and had a similar problem. At first I tried to find any leaks... No luck. Then I changed the cap, and the code changed to "incorrect flow" on the evap system.

Turned out, someone put the purge valve in upside down! It is clearly labeled "bottom" on one side....but someone had ignored it. Another good check is that one outlet of the valve says "VAC". You should be able to follow that line into the engine block, rather than it traveling to the back and into the fuel tank. Not sure it will help, but something easy for you to check!

I have no idea why the previous owner would have put it upside down. But hey, that's what buying a used car is like!
04-25-2013 01:05 PM
G-LOVE I don't know if anyone else had this issue, but when I was going through my new 2002 Sport, I noticed my gas filler tube (the metal piece that gas cap screws into) was rusty, and upon cleaning it, I found 5 small pin holes under the corrosion. When I blew into it with my hand over the end, I could feel air escaping. I spot welded the holes, then painted the hole thing with POR-15. She is tighter than a drum now.

ALSO NOTE: That to double check if the code is fixed, disconnect your battery for 5 minutes, and see if the code comes back.

-Jim
04-25-2013 12:36 PM
d6cat
P0455

projecttj97, I have a 2002 Grand Cherokee 4.0, keeps setting P0455 & P0442. I can't see any cracked lines or hoses. I have smoke checked the system (I haven't figured out how to close the vent, so I plugged the end of that hose) and not found any leaks. The system will hold pressure, only slowly leaking off after over an hour. I thought maybe the leak detection pump wasn't closing when commanded so I replaced it. Still the same problem and no leaks found. Any suggestions?
04-20-2013 12:49 PM
ChaddG those cracked hoses will pop that code, look at the underside of the hose under the one with the green cap, mine was cracked where I couldnt see it
04-20-2013 11:51 AM
projecttj97 I believe the jk has the 3.8 and this is the same motor as the caravan. The cars had a evaporated hose that would attach behind the throttle body and the would cracking all the time
04-20-2013 11:00 AM
Beastmaster
Quote:
Originally Posted by JVLemur View Post
I have the OE cap and just got P0456, any cap you'd recommend Jerry? I'll start with that, never had the code before.



Can you post pics of where your leak was? I'm getting the same code and if a new cap doesn't do it I'm hunting for the leak, all help is appreciated.
Okay, I know this thread is in the TJ section and was started about code P0455. There was some mention of code P0456 here and I have a JK but I think the problems are similar with both models. The thing that drew me to check the tubing were the pics in post #13 of this thread.

I'm at work but can post some pics later, but the JK has a tube that runs from the top of the engine, across and down in front of the battery. This tube looks like it had been rubbing against the battery and this is what I repaired.

Looking back, since I did the gas cap and repaired the tube a day apart and it took 5 days for the code to clear, I'm not 100% sure which (or both) cured the problem.
04-20-2013 08:45 AM
ChaddG you guys nailed it b4 me. I had that code. replaced the line with the green cap, dealer only, 32.00 its 2 hoses, cleared my codes, all was fine. drove with that code for 5 years, no probs.
check the rubber fittings that go to the purge valve<by the green cap> get some rubber hose and d.i.y. 2 chunks to connect the plastic to purge.
you will need a code reader to clear the code.

mine started with minor leak code, then major showed up.
your gas cap is probably fine. <unless it's a locking one> they leak through the keyhole
I have a post about this 0455 code too
Good luck
04-19-2013 11:34 PM
JVLemur
Quote:
Originally Posted by projecttj97 View Post
i'm a tech and my speciality is dealing with emission type codes. And they can drive you crazy. alot of the time i see people get a locking gas caps or stant gas caps and they leak right out of the box. Always buy from the dealer. 2 i always check all the hoses cause most of the time someone has knocked them off or they have started to crack, Alot of times on the 4.0l it's the 90 degree vac hose as stated before. Which you can get from any autoparts store. Any other cracked hose that have been custom formed need to be bought from mopar and can be alittle bit of a task trying to get the correct ones. Also on chrysler i would caution you on smoke testing these without knowing what valves need to be grounded to close to seal the system. But as stated before most of the time evap leaks are simple cracked hoses or gas caps. Any other questions feel free to ask me.
Any recommendation of aftermarket gas cap? There's mopar ones on quadratec, would that be good?
04-19-2013 11:28 PM
projecttj97 i'm a tech and my speciality is dealing with emission type codes. And they can drive you crazy. alot of the time i see people get a locking gas caps or stant gas caps and they leak right out of the box. Always buy from the dealer. 2 i always check all the hoses cause most of the time someone has knocked them off or they have started to crack, Alot of times on the 4.0l it's the 90 degree vac hose as stated before. Which you can get from any autoparts store. Any other cracked hose that have been custom formed need to be bought from mopar and can be alittle bit of a task trying to get the correct ones. Also on chrysler i would caution you on smoke testing these without knowing what valves need to be grounded to close to seal the system. But as stated before most of the time evap leaks are simple cracked hoses or gas caps. Any other questions feel free to ask me.
04-19-2013 11:02 PM
JVLemur
Quote:
Originally Posted by Jerry Bransford View Post
Aftermarket locking gas caps often leak air through the lock mechanism. I'd switch back to the OE gas cap and I'll bet the problem goes away after that.
I have the OE cap and just got P0456, any cap you'd recommend Jerry? I'll start with that, never had the code before.

Quote:
Originally Posted by Beastmaster View Post
This forum is the greatest!

I had code P0456 come up a few weeks ago and searched the web and was lead back to my favorite Jeep forum.
Reading this thread (and a couple of others) I decided to try a couple of things:
I purchased a locking gas cap (which I was thinking about doing anyway) but it didn't help.
Next, I checked out the tubing that routes near the battery and sure enough, it was worn on one side. I slapped on some RTV sealant and wrapped it with wire wrap (you know, the ribbed kind that comes in rolls) but the light didn't go out.
I had resigned myself to the fact that I'd have to go to the dealer and pay to have it checked out (I have an extended warrenty but have a $100 deductable).
Low and behold, on day 5 after my repair, the light didn't come on and it's still off!

I love this forum, thanks for the help guys.
Can you post pics of where your leak was? I'm getting the same code and if a new cap doesn't do it I'm hunting for the leak, all help is appreciated.
04-19-2013 10:53 PM
Beastmaster This forum is the greatest!

I had code P0456 come up a few weeks ago and searched the web and was lead back to my favorite Jeep forum.
Reading this thread (and a couple of others) I decided to try a couple of things:
I purchased a locking gas cap (which I was thinking about doing anyway) but it didn't help.
Next, I checked out the tubing that routes near the battery and sure enough, it was worn on one side. I slapped on some RTV sealant and wrapped it with wire wrap (you know, the ribbed kind that comes in rolls) but the light didn't go out.
I had resigned myself to the fact that I'd have to go to the dealer and pay to have it checked out (I have an extended warrenty but have a $100 deductable).
Low and behold, on day 5 after my repair, the light didn't come on and it's still off!

I love this forum, thanks for the help guys.
04-08-2013 10:36 PM
BIGDINO
Quote:
Originally Posted by FreedomEdition View Post
That's a nice looking gas cap. $27 bucks! ...it better do the job!
I hear you! $27 bucks was a lot for a gas cap, but I haven't had any problems with the CEL or evap system since I got it (knock on wood).
Dino
04-08-2013 01:42 AM
FreedomEdition
Quote:
Originally Posted by BIGDINO View Post
Hey, unfortunately I don't know the actual part number for the gas cap. I found my receipt from Firestone and they listed the gas cap as Article # 7030260 ID 1011TN. The cost was $26.99. I recall the guy telling me that he ran over to Autozone for this fuel cap, but I cannot locate it online. I took a pic of my fuel cap. Hope this helps!
Dino
Hi BigDino! Thanks for the response. That's very nice of you to provide a photo. That's a nice looking gas cap. $27 bucks! ...it better do the job! I can see there are so many jeep owners with this EVAP problem. Once I decide on a new cap, I'll change it, along with whatever vac lines that look questionable, and then Reset the computer and see what happens.

Thanks Again for Your Help.

John B.
04-06-2013 12:29 AM
BIGDINO Hey, unfortunately I don't know the actual part number for the gas cap. I found my receipt from Firestone and they listed the gas cap as Article # 7030260 ID 1011TN. The cost was $26.99. I recall the guy telling me that he ran over to Autozone for this fuel cap, but I cannot locate it online. I took a pic of my fuel cap. Hope this helps!
Dino
04-05-2013 09:28 PM
mpbannon60 I found an evap leak on a steel hose going back by the coil mount so I'd say check all your lines
04-05-2013 09:27 PM
FreedomEdition Hi BigDino... you said the Firestone guys replaced your gas cap... what did they replace it with? Make/Model?

Your Help will be Greatly Appreciated,

John B.
04-05-2013 09:22 PM
FreedomEdition
Home Made Smoke Tester?

Quote:
Originally Posted by relgnarw peej 2002 View Post
If all else fails do like I did and spend $20 on a homemade smoke tester for your evap system. I was bullied by that code for a year n come to find out the replacement gas cap i put on from autozone was crap and leaked worse than the faulty cap that needed replaced.
Hi relgnarw peej ... I've got codes P0442, P0455, P0456... EVAP Leaks small/large... been there forever... gonna try to eliminate them as I want to sell it. I'm interested in how you made your "homeade smoke tester". I also have gotten gas caps, several, from Autozone. Did you ever find a good cap, and if so, where did you get it?

I have a 2003 Jeep Wrangler Freedom Edition 6 Cylinder.

Your Help will be Greatly Appreciated,

John B.
02-13-2013 02:06 PM
fab86 I just wanted to thank the OP for the thread, and all of the folks who replied with the useful info. Geez, I love this forum, my wallet more so...
01-25-2013 08:15 PM
BIGDINO So I've been scratching my head over the p0455 code for the past month. I read pretty much every thread on WF along with other jeep forums. I did what everyone recommended - replacing the gas cap with a factory cap from an auto parts store and disconnecting the negative terminal on the battery to reset the CEL, following the fuel lines and looking for cracks, etc., but nothing worked. I didn't find any cracks so I assumed that the leak was somewhere near the gas tank. I didn't want to bite off more than I could chew by dropping the fuel tank, so I decided to suck it up and take it to a shop to get it smoked.

I just dropped it off at Firestone and they first asked me if I had replaced the gas cap (which I thought was pretty cool - I feel like the stealership would have just taken my jeep and not asked me about this before performing a diagnostic check and billing me.). I told them about everything that I've done to try to remedy the CEL code, so they performed the smoke test. Turns out that my new factory gas cap, which I purchased from a reputable auto parts store, was the culprit. The Firestone guys said that it wasn't the right gas cap, thus not sealing correctly, and that my fuel system did not have any other leaks. They replaced the gas cap and I'm good to go now.

So, if you get this error code in the future and try everything that is recommended by the pros here on WF, I suggest paying the extra $9 to buy a second factory gas cap just to rule it out before you pay a mechanic to do a diagnostic test. It would have saved me $128.00 today!

Dino
12-06-2012 09:32 PM
relgnarw peej 2002 If all else fails do like I did and spend $20 on a homemade smoke tester for your evap system. I was bullied by that code for a year n come to find out the replacement gas cap i put on from autozone was crap and leaked worse than the faulty cap that needed replaced.
11-21-2012 06:26 PM
OK_TJ I had the same problem this summer. It was the short hose shown in one of the pictures. It was cracked on the back side where you could not see it. No problems since replacement.
11-21-2012 02:51 PM
TheBigMan My wife's Libby throws the same code. I changed the gas cap a while back, didn't do a thing. I'm sure it is a dry-rotted hose that I haven't been able to locate yet. She's been driving it around for a while with no issues. The only issue we will have is when we go to get it inspected...it can't pass with a CEL on.
11-21-2012 01:35 PM
klkb Does anyone know if the EVAP designation after the code mean anything more specific?
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