I put a new AEM Cai on my 05 cobalt and now after every couple of days my check engine light comes on. I took it to my buddy and we put it on a code reader and the light is on because the engine is running to lean. We erase the code but it just back on after a few days. Anything I can do to fix this?

 

check all fittings on intake
Check around the MAF for leaks

If you can't find an air leak, it's probably normal and unpreventable.

 

Pretty common for a cai to cause a long term fuel trim lean code to be thrown.
Since the cai flows better, the ecu is getting a lower than expected reading from the maf - it thinks there is less air flowing than there is.
If the cel bothers you a tune can get rid of it - if it doesn't bother you then don't worry about it. You are not really running lean but you likely won't pass inspection with any codes set (assuming you have to pass inspection of course).

 

There was an update back in 06 to the SS/SC's calibration that helped stop the P0171 codes from popping ...... your dealer can flash that update for you .