So I have a 07 Tahoe, it has a 5.3 v8. So a couple weeks ago I noticed it having a lifter tick. But not to bad of a tick, recently we have been having misfires and I honestly don’t think I’ve heard the lifter tick anymore. But I could be wrong, it’s caused it to back fire. I took it muffler shop to get them to clean out the catalyst converters. Before that I had a exhaust leak. Got that fixed then to the muffler shop for clean out of converters as said above.. It did fine for a couple days, now yesterday I got gas at Walmart, got going down the road the stabilization come on the dash and the engine light started flashing and it bogged down and acted like it wanted to die at the stop signs. It’s pulling codes for p0300 which is a engine misfire detected and cylinder 2,4,6,8. I try and turn on the air conditioner and after a couple mins of sitting it will completely die if the compressor kicks on.. we got some spark plugs last night. Put them in still nothing. Checked the ohms of each plug wire, good, checked fuel injectors (good) what do you think it could be? Bad engine all around? Vacuum leak? Lifters compromised 😭
please help I’m stuck.

 

Welcome to the forum.

I remember that the GMT900 SUVs had lifter problems show up due to the AFM. Resulted in a lot of engine replacements under warranty. Could be your problem.

 

Welcome from Florida. I would check for a clogged cat. I know you said you had them cleaned, but I would check that

 

+1 if the misfires are accumulating only on 2468...all on one bank...check things that would effect only one bank....clogged cat...remove the precat 02 sensor from the exhaust on that bank to bypass the cat.

Other things that effect one bank would be a bad 02 sensor...unplug the 02 connector so the truck runs in open loop

 

yeah not sure what to do, especially if the 4wd trying to turn on from it being in auto on the switch. Than of course the service traction control come on and service stabilizertrak comes on and it barely has any power at all. We’ve cleaned the throttle body, no change. I don’t know what to do. As far as EVERY CYLINDER HAS A MISFRE ON ONE SIDE. And pulling for the engine misfire detected

 

Bad ground wire