2002 5.3 MAF code on runs rough after replacing MAF

[Mark Lent]

Replaced Mass airflow unit after getting code. ran decently for less than a week code came back. replaced mass air flow sensor again code would not clear attempted three times to clear,  Check engine light on runs crappy no power valve chatter only when driving. in neutral runs like a champ

[davester]

Google "GM code XXXX" where XXXX is what code you are getting.  Then read through the diagnostic procedure for it.  It will include a bunch of things to check prior to "replace MAF sensor"...