CEL light + fuel cap = ???
 

The other day I put gas in my W210 E320. I guess I did not turn the gas cap tight enough. Sure enough, later that evening I got a CEL message. I borrowed a scanner and it showed as P0156 and P0161. From previous expereince I know this is for the O2 sensor (rear one).

Anyhow, I turned the gas cap (it was 1/4 loose) and resigned myself to taking my car to my favorite indie (Mr. M.B. Motors) to replace the little dickens.

Yesterday the CEL light was off. I drove the car for over 100 miles and no CEL.

My question is this. I know that a loose gas cap can cause the CEL to come on. But when the CEL comes on as a result of a loose gas cap, does it put out any specific code, or does it light up any fule/ignition related code (such as the O2)?

I don;t mind having the to replace the O2 sensors, they are fairly cheap for my car and enrique goes easy ont he labor part. but I am just curious about what kinds of codes does a loose gas cap produce.

Hope everyone had a great Turkey-Day.

And for all of you Notre Dame and Texas fan, I am glad you survived your respective scares. Having ND win helps USC's SOS ranking with the computes and having Texas undefeated will make it all that much sweeter come Rose Bowl day when SC finally exposes Mack Brown and Vince Young (I love sneaking football talk into the Tech Help threads :D )

Thanks. :eek:

Codes P0455/Large Leak and P0442/Minor Leak are the codes that are stored due to a loose or missing gas cap.

Thanks.

OK, then I will assume that the O2 sensor is in fact bad and the CEL will light up again.

Oh well...

thanks.