I recently bougt an autometer afr gauge so i could have a general idea if i'm running lean or rich under boost. Got it, installed it, and everything looked good. Then i noticed when i started the car up it reads lean as far as it can go and then it slowly climbs up as after about 3-5 minutes. The car in the meantime is idling fine and dandy though. I talked to my shop teacher about it and he said it might be my coolant temp sensor. And actually i know for a fact my cts is bad.... but could that be causing this problem or is my gauge just wack?

 

conventional oxygen sensors are useless until they are at operating temp

 

And not to mention during the warm up process, the motor is running lean to begin with.

But i second alexdemin's theory too.

 

o, cool.... so its not uncommon i take it. Appreciate the help guys! thanks....
Anthony