trying to track down this low end stumble that seems to clear up past 2-3k rpm. just installed new opti, checked and double checked wires to make sure they were in RIGHT, and plugged in RIGHT...even swapped out coil and IM from my caprice, fresh tank of gas etc etc...still stumbles on the low end...

so i looked at the header bolts, and damn if #8 had backed out, the last one of all!!

didnt get to tighten it yet,,

but heres the questions;.....anyone else have a low end stumble / miss with a loose header bolt...im running mac midlengths....and seems like when my m22 plug fell off the air fitting it kinda did the same thing, cept i dont seem to hear the leak...so much...but the car clears right up after 3k rpm...

i will psot more after i tighten it down and check the rest...car was too hot, and i was too sweaty to try anything else earlier...

thanks for all who were checking ou my other posts!!
wish me luck!
b

 

Check your spark plugs as well to make sure theyre properly torqued down right.

 

One loose header bolt should not cause a stumble.

 

If its allowing the exhaust to pull (educt) air into the loose header flange, its going to cause a false lean condition, and the PCM will start adding extra fuel to that bank, possibly causing a misfire.

 

Ive found the A4's to be very sensitive in certain lower RPM/load conditions.. if anything is wrong with anything you start to notice it at the lower RPM