The check engine light came on today while I was cruising on the freeway on the way to work. As soon as I let off the throttle, it went away. Cruise for another minute or so and it was back. Let off the throttle it was gone, etc.... Any ideas?

 

Looks like you have an S5 from your picture, just pull the codes... That will give you the best description of your problem.

 

Does the code stay even after the indicator light goes away? Or do I have to drive and pull codes?

 

The code is stored in the ECU. It will come up if you pull the codes, the CEL doesn't still have to be on for the codes to be in the ECU.

 

http://www.johnr.com/cpucodes.html

 

Thanks Rotary Rocket... I Was pulling my hair out on how to do that...

 

Bad O2 sensor. Good thing I already have one on order