My check engine light came on Friday morning before I left for LA, reset the OBC and it went off and didn't come back on until this morning when I was getting ready to leave LA..There didn't seem to be any problems so I just drove it home almost 420 miles with one eye on the road and one eye on my dash!

I believe I have a vapor lock problem somewhere in the filling tube that has been intermitent. For a while I could only pump about half a gallon of gas at a time before the pump would click off so I was just pumping gas at about half the usual pressure. Took the filling tube completely off and there was no obstruction at all, problem persisted for a while and now only happens here and there.

I have had 5 gallons of gas in the garage for a month or so I planned to use for some atv riding but the weather has been so crappy I figured I'd put it in the Jeep, I'll tell you it was one slow drain and the gas kept backing up the fill tube. This is from one of those stupid spill proof gas cans that release the fuel slowly to begin with for this purpose.

Anyone else ever had this problem?

 

On my 2007 Hyundai Elantra, which I don't have anymore, I had a check engine light on. Took it to AutoZone, the guy working there said to screw my gas lid on tighter and drive it for a few minutes. Long and behold, the light permanently left. From there on, I'd screw it on tighter. Never had the problem again. Could be several things.

 

get it read by autozone..had both O2 sensors out and drove it that way til i rolled it..around 40,000 miles.

 

get it read by autozone..had both O2 sensors out and drove it that way til i rolled it..around 40,000 miles. >>>>>>>>

Where are the 02 sensors located?

 

I drove with a bad o2 sensor for about 20k before I gave in and got it fixed. It's not an immediate issue and those dam things in the odb2 cars are about $100 to replace.

There are two sensors, one just below the exhaust manifold where the downpipe is, and another after the cat. They help with air/fuel mixture and to monitor ur catalytic converter. I've heard that if you run it like that for a while it makes the cat go bad but mine is just fine after I replaced the sensor. The CL light hasn't been back on since.

 

If they were bad would the engine light stay on even after resetting the OBC?

 

Yes, it would turn right back on.

 

OK, well I reset the OBC and the engine light went off and I've driven it for a good half hour or so and it hasn't come back on yet.

 

What year is your jeep? I know for sure that an odb2 vehicle would be popping the CEL for a bad o2 sensor, but I can see how maybe a pre-97 vehicle might act differently. Give it some time to warm up the cat and then it should begin reading as faulty. Did ur reader tell you which o2 sensor was out before?

 

I have a 97 with the 5.2. The mechanic told me if the light goes off after resetting the obc and doesn't come back on within a short time it's probably something with the fuel cap. I haven't had it read and when I smogged it he said if there was a problem somewhere it should of popped up then.

 

When you reset the ecu it take 80 to 100 miles for it to reconize a problem

 

if it passed smog then he's right it wouldn't be your o2 sensors, since that's one of the major things they check when doing the engine diagnostic.

Sorry, guess I can't help ya out then I havnt had an issue with the gas cap before, but with electronic sensors anything is possible heh

 

Ok, so my Jeep sat in the garage for about 5 days, pulled it out on Monday and engine light stayed on. Reset it and have driven nearly 300 more miles without it coming on or having any kind of problem.

I think I may just have a bad gas cap.

 

Ok, so I bought an code reader at AutoZone(here in CA they aren't allowed to read your vehicle unless it's a repair facility) got code 442 which is for a small emissions leak related to gas cap, cannister, or minor vacuum leak. I've replaced the gas cap, previous one didn't lock so I got a locking one. If that doesn't fix it I'm not going to worry about it because the only problem would be passing a smog test which Isn't due for 18 months.