1999 Jeep Cherokee Sport My "check engine" light is on. I stopped at a parts store, they plugged in their diagnostic tester, and the result is error PO505 bad idle air control valve. I remove the valve, cleaned it with carb cleaner, put it back. Check engine light is still on. I have not driven the car yet, just started it. So, two problems. I did not clean down inside the metal sleeve, just the outside of it. So I'll have to take the valve off and do it again. But, there is a rubber "O" ring which I lost. Can't find it anywhere. Does anyone know what size I need to buy as a replacement? I'd like to buy it before I take the valve off again. Thanks.

 

With CeLs, even though you May have fixed the issue, the CEL remains until the computer verifies its fixed with some driving. Doesn't just disappear unless you cleared it yourself.

 

Can you maybe just park at ACE hardware, take out the two screws and take it in and select an O ring? I'm pretty sure it needs that to seal. They may have different thicknesses in the same diameter. Get one that fits snug.

I've never used a scanner and don't have OBD. That said, I'm pretty sure if you leave the Neg cable off the battery overnight it will clear the codes.

 

I did forget that part. Yes you need the o ring. Check mopar parts over stock or similar and they show the part number for that o ring and then you can research it and match the thickness. Easy easy