First of all, the car does'nt code at ALL. On the road, I can tell its not as "peppy" as it needs to be. I can hear a loud leak like an exhaust leak under the plenum or at least that where it sounds like its coming from. If I put my hand at the muffler, it does'nt have a smooth idle as if its missing.I NEED HELP!!! I can rev up the engine from being in PARK and it does fine. Would and exhaust leak at the manifold cause this or the intake gastket gone bad or both? I'm hoping it is not the injectors. The problem in so far as the loud exhaust leak has progressively gotten worse over the past 3 weeks. I also noticed it sounds as if its coming from the passenger side more so than the driver side. ANY advice for my 3.1 V6?

Ken

 

How is your ignition system? I new distrubutor cap, rotor, and plug wires will go a long way on making your engine run better.

 

Nah...did the tuneup thing last month.The loud exhaust leak under or near the plenum is concerning me though. I could tell it ran better after the tuneup, but the exhaust noise has gotten worse and car idles bad. Maybe the donut gasket in the Y-pipe has gone bad or maybe the exhaust manifold gaskets need replacing. That might cause it to run rough.Dunno.

Ken

 

TAKE IT TO A MUFFLER SHOP & have them confirm what ya may suspect.
I can tell ya that those original manifolds do crack due to Bubba the mechanic lifting car incorrectly. Most people put the lift on the exhaust system & that causes all sorts of trouble.
Take it to a good muffler shop for their help.
Yep cracked leaky exhaust or exhaust manifold sure will kill a decent idle.

 

If the leak is coming from the Y-pipe and/or donut gasket, will it sound as if it is coming from underneath the plenum just due to the echo bouncing off the firewall?

Ken