So, I have a 1991 Z28 l98 car, with original g92 cats, cats have about 160k, engine about 60k. I thinks these suckers are done. The exhaust seems very heavy and very deep sounding. I think my I am having what I determine is a small lack of low end performance, not horrific by any means, and the thing is developing a pattern of small exhaust leaks at exh manifold gaskets. These leaks are more prevelent at cold engine temps or at startup. The ignition system is currently all updated and the fuel delivery seems appropriate, albeit slighty rich.

Do ya'll think im on the right track. Honestly, I think with 160k, the cats need some love.

Advice appreciated. What has been your experience.

Scott

 

sounds to me like your on the right track . i would be very suspect of a cat. with that mileage . an engine must inhale & exhale well to perform o.k. . good luck .

 

I would replace them ASAP... had 86,000 on my 91 z and it was very doggy until I replaced them, spend extra for stainless if you plan on keeping her.

 

Exhaust manifolds do not have gaskets.

Only headers use gaskets.

Your leaks are somewhere else.

Magnaflow, catco, and random technology are all good choices for replacement catalytic converters.

 

At your advanced age, Uncle, I'd like you to remember about the inhale & exhale business

JamesC

 

thats one more i owe you . i'll get you yet .