I just bought myself a '94 z28 A4, cause I love the F-body n i've always wanted one, but i have a few minor issues I want to work out. First issue is my lt1 sputters a bit during idle and during low rpm's accelerating it boggs a lil. It also smells like it burning fuel a lil rich. It seems it could be as simple as a fuel filter or plugs n wire, but Please gimme some advice from anyone who knows the lt1 best...THanks

 

is your check engine light on ? do you have black sute coming from the tail pipes and on your rear bumber ?

 

yeah my check engine light is on, but i dont notice much black smoke. here are some of the other things i noticed that might contribute to the problem; the cat. is replaced with some sort of glasspack (thats what they said when i got the rear exhaust done...idk why the previous owner did this,,but w/e) and its mig welded in which seems to leak a little. Could the 'replacement cat' be clogged?? Also when I looked at the exhaust manifold one of the wires on the sensor is disconnected (pink in color) The last visible issue is the infamous ripped intake elbow. I patched it up a little, but could this bypass affect the performace??

 

The glasspack muffler is a straight-thru design. It can't clog unless you try to stuff a piston through it!
It sounds like you're describing your oxygen sensor being disconnected. And that would explain why the engine is running rich, since the oxy sensor monitors your air/fuel mix.

 

yup thats why i asked if he has black sute or wwhat ever it is lol on the rear bumper cause it sounds like the o2 sensors went bad like mine did and acted the same way till i replaced both o2's and its fine now just make sure you buy a good brand of o2's if it is whats acting up.....cause mine is starting to act up again lol

 

try unpluging one of the o2 sensors and see if it helps if not try the other one ... they are before the cat well in my car they are ..just unplug one at a time and see if it does a bit better

 

Thanks for the advice, Ill look at some replacement o2's and hopefully I can get a new intake elbow.

 

An easier way to test is to unplug your MAF, it will force the car to run in open loop mode where it ignores the O2 sensors. If unplugging the MAF works you can try the O2's individually, but trust me, the MAF connector is much easier to reach!

Also, since the check engine light is on you could try and get the codes (autozone etc. won't be able to do it, there's a guide on how to blink them off at the top of this section).