Exhaust System Upgrade

[Stratosurfer]

All,
I'm still on stock exhaust on Tahoe and Sub. From reading some symptoms, I'm convinced both cats are to some degree plugged: So I'm looking at either cutting the cats off, replacing with 'test' pipe and replacing the crossover pipe, or biting the bullet and buying two new systems from either JK or Heath: they both seem good.
My question is this: how much more performance/mpg will I get with a newer matched system turbo back w/crossover pipe over just a new crossover pipe and cat gone (for inspection...)?
I really want to stay SS, and don't like the outfit that sells the SS exhaust systems: does the aluminized tubing hold up as well??

Thanks

[DaveBr]

All you have to do is unbolt the 3 nuts on the flange from the downpipe to the cat. They will easily pry apart. Move the cat over about 1/2" so the flane studs don't line up with the holes. You will have a gap between the 2 flanges. This will tell you 2 things after you test drive it like this. It will tell you how plugged your cat is and how much difference a free flowing exhaust will make.

I did this and it told me it was time to bury the cat.

[Robyn]

Hmmmmm I smell a dead cat somewhere :D

A good 3-1/2 or 4 inch system will really help.

An outfit called "Frozen boost" sells a CAT lookalike that is just a pieve of pipe within a can that gives the apearance of a CAT but also does not foul up flow like a hollow can does.\

If you must go through inspections, these are a nice plus to let folks see what they need to see.



The Cats really plug up with crap over time. This causes real drastic back pressure increase which slows the flow down, resulting in poor turbo performance as well as higher EGT

The mufflers plug up too.


Missy

[ToddMeister]

When I bought my 95 about 7 years ago the cat was plugged, causing it to run very poorly.

Put on a 3-1/2 inch Kennedy aluminized system (turbo back) and it is still performing well.