My car pinged bad, It stopped after I replaced my maf. You might try cleaning yours.
Have you made any changes to the car?
how old is the gas thats in there ?
mywhite89 said:A restriction in airflow can cause this, like a very dirty air filter
cbt said:how about some plugs and wires ?
I could see it running lean when its cold, But why would it run lean if the air filter is dirty?