Guys the wife’s Tahoe 07, 5.3, LTZ 2WD has 234k miles on it and this code popped up. I changed the plug and it looked like it was ok. So the guy at NAPA said try the ignition coil, so I got just one. We never changed the plugs (doing that now) or done a tune up (while deployed the dealership informed her it was running fine.) My question is
1. Should I replace all 8 ignition coils and wires or should I
2. Swap the one and see if it clears the code up?
Mind you I just need it to get to Feb so I can get rid of it. (It has led a hard life and I want to send it out to pasture!)

 

234k miles??? Dang lol. I would change all the plugs and wires first since its past time to do that. I would not replace all the coils, that is a waste of money, unless we are talking about a Ford mod motor.

 

Plugs changed, ignition coil for number 8 changed and it's still misfiring WTF over? I'll tackle it in the morning thanks chevymec.

 

Did you change the wires also?

 

When my 5.3 started going downhill @ 173k it started with misfire on cyl #1, month later misfire cyl #3 and it was not caused by the coil packs, plugs, wires, or injectors. The camshaft lobes were worn down on those cylinders.

 

OK, guys it's threw, looks like TXSZ66 was right that cyl was full of oil this morning. Were in the process of plan B.

 

NNBS are having problems with this, I have rebuilt several due to the camshaft lobes wearing down. We believe it was a bad batch of cams installed, but no bulletin or recall to my knowledge yet.

 

Happened in my 06 classic too.
https://www.performancetrucks.net/fo...-514292/page2/
There is a pic of the cam on page 2