I have a 02 1500hd silverado. Its my Work/trailer puller truck. It recently started becoming sluggish and missfiring alot. I checked the trouble codes and got a radom misfire on all cylinders code and a lean condition on all cyl. I started with new intake gaskets (thinking it was a intake vacumm leak) didnt fix it, so I put a fuel pressure regulator in (still doin it) Next I put new plugs and wires on (no change) Then after some time I put a new fuel pump and fuel filter in (old one shat) This cleared the lean condition but not the missfire run crappy thing! LOL Now Im left scratchin my head at my empty wallet and wonderin why its still doin it and even most of my best ls1 freak friends have run out of answers for me. Has anyone here had this prob or know how to fix? The truck is 4WD and has 130K on it. My only mods are a flowmaster cat back and a 2" leveling suspension kit. PLEASE HELP! like most stubborn home mechanics IM REFUSING TO TAKE IT TO A GM DEALER!

 

Are the O2 Sensors still the original ones?

 

catalytic converters plugged up???

 

check and clean the MAF, check the O2s

 

Yeah the O2s are original as far as since 46k and the cats are flowing fine Ive checked for abnormal temps in front of them with a raytek heat gun... Ill try new O2's but its not throwing a code for them.. Could they still be bad?

 

if the O2's are reading lazy(not switching) properly they could be "bad" but not bad enough to throw a code. If you have any way of telling which cylinder is missing and when that would help alot...also another thing to check would be fuel injectors.......

 

id be leaning more on your fuel injectors..depending on what brand of gas you use..ive seen fuel injectors plugged up completely..the guy was useing the cheepest gas he could find..this is something that no fuel injector cleaner will fix..before you go spendin any more money pull your fuel rails off and pull your injectors out and tap them upside down in your palm..when you replaced your filter was it plugged really bad?? if so that could have helped lead your pump to **** on its self

 

I would also check the crank position sensor, sounds like symtoms of one going bad. You have to unbolt the starter to replace this sensor.