some OBD 2 codes can't be cleared by a simple bat. disconnect but thoses are only the emssions codes you got a buggered coolant over flow sensor and since that doesn't "effect the environment" the computer couldn't care less if you want to reset it by a bat. pull

Agreed not all codes can be cleared this way. You need a scan tool to clear all. If you are lucky you can find one at Kragen or somewhere similar for $25 bucks and up. Same with JcWhittney- 24.95-399.99. I think it would be cheaper in the long run for ya to get a 60 buck scanner because you can use it again and again instead of payin a shop 100 bucks a shot.

Okay guys, I getting codes that do not pertain to my Jeep. (A) The first one doesn't even exist. (B) The second says there is a problem with the A/C clutch relay (mine doesn't have A/C), (C) The third is showing a lean condition. How can I fix these?? I have just replaced the Oxygen sensor.

Something is telling me that your scanner has the incorrect make/model/year, unless there's another way you get stored codes from your computer that have nothing to do with your jeep. "Lean Condition" with a new O2 is usually a manifold vacuum leak.

I retrieve the codes according to mt "Haynes" manual. After driving, turn off the engine, turn the ignition to on, then off, then on, then off, then back on and leave it. The codes show up as flashes of the "check engine" light. Is there another way to retrieve the codes? If I buy one of the retrievers from JC Whitney, will it work on other vehicles???

if you got codes that don't pertain to your jeep and you did it with the key trick then.. you counted wrong. the cheep scanners at jcwhitney are for 97 and OBD2 cars. in order to get one for your's it will have to be jeep specfic and will only work on other YJ's.

I have a 94 with no ac and any time I check mine with the on off method I get the AC one also... I also get another one, but I cant remember what it was, but it was also something that I didnt even have... I was told that the computer on the 94 and 95 jeep was set up as if you had all of the options (I wanna say it is the same as the cherokee) IE a/c ext, and that those codes will always come up with the on off method... These codes will not cause the check engine light to stay on or even come on though... You may actually want to buy the scanner or go and get it check.. I want to say that autozone had a thing going for a while where they would run it for free... you may want to try that... But hey... if it is running ok, then dont worry about it... My wife has a 99 Isuzu trooper and if she forgets to tighten the gas cap till it clicks then she gets a light... heck the light on that thing comes on all the time for no good reason... Its just another way for the dealers to make some cash...

I was getting odd codes on a different vehicle (non Jeep) It ended up being the computer going bad. Just something to think about if all else fails.

you'll always get the AC code if you don't have AC. Lean condition, new O2 sensor= cracked exhaust manifold or loose exhaust manifold bolts or air getting into the exhaust manifold through the head to manifold gasket (if it has one). The crack doesn't have to be big or make any noise, if there's a crack air will get in and the O2 sensor will read lean all the time. That's why the light is coming on, it doesn't come on for AC or battery disconnect.

Would a crack or loose bolts cause it to use an excessive amount of gas? If not, what would? It runs fine, no miss, good acceleration, just uses way too much gas. I can't find any leaks.