Hey guys I'm in need of some help. my 99 silverado 5.3 has developed a terrible missfire. The truck is barely drivable right now. I scanned the ses light and got P0101,P0300,P0332,P0420. I replaced the plugs and wires and it seems to have made no difference at all. I don't want to continue wasting money on parts I don't need. So if you guys have any input on things to check that would be great!
Thanks,
Matt

 

What I do is clear the codes, drive the truck, then scan 'em again to rule out any old history.

That aside, rule of thumb is to start at the lowest code first; in your case, the MAF. Also, as it is the common denominator to your additional random misfire, knock sensor and converter codes.

Allan

 

Thanks for the response! Is it possible my Maf code is caused by the maf being dirty?

 

Sure could be.

Allan