My 2008 CX-9 (about 105k miles) recently had the gas cap light come on. We tightened and then replaced the gas cap and went to our local mechanic to reset the gas cap light (he did not save the codes) to see if it would come back on. They reset the gas cap light and then a few days later the check engine light came on. Went back to the local mechanic and this time he mentioned since the light was reset, there were no codes and that we needed to drive the car for 25 - 50 miles to capture codes again. Is it normal that after a reset. Does anyone know the proper way after a reset for codes to be generated again?

Thanks....

 

My service engine light came on after i would drive over 60 MPH and my car would shake like crazy and sounded like it wanted to shut off. I changed the throttle body and then the light came on for my gas cap. changed it and again the check engine light came on. I put in a canister purge valve so fingers crossed it's fixed but at this point who knows.

 

Emissions readings take a while to register, so yes this is normal. Keep driving until the CEL comes back on; could take 2-3 days of driving.