I am new here and have a problem with my 96.
I was wondering if a bad lifter would cause that engine bank to run rich?

The full story is: my 96 has a bad misfire on cylinder 4, has a constant lifter peck on cylinder 4, definite valvetrain noise, and bank 2 has showed up as running rich several times on my ses light. I took it to a mechanic and he thought it was a fuel injector, but the plug looks like all the others. He did say the compression in that cylinder was 20 psi lower than the others.(110~130) and tended to build up more slowly. It possesses no symptoms of bad rings and passed the vacuum test easily. I feel pretty confident that i have narrowed it down to a bad lifter or bad fuel injector, which is why i was wondering if a bad lifter would cause these symptoms because the mechanic said he didnt think it would and that 4.3s were famous for lifter noise.
Thanks very much for any help!

 

yes a bad lifter or cam lobe will cause a misfire have you checked to make sure the valve adjustment/tightness is correct?

 

Would a bad lifter(or improper valve clearance like you said) also cause that engine bank to show up rich(by 'rich' i mean it showed code p0175, which doesn't necessarily mean its running rich, but at least theres not enough oxygen in the exhaust)?

I have not checked the valve adjustment yet, but i can put a rod against that valve cover and a large vibration can be felt with each peck of the lifter, if that helps determine anything.

Also, would any of those problems show up in the compression?