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What brand CAT is best? Should I go high-flow?

Blacknight02GT

Blacknight02GT

New member
So, recently my stock cat converter clogged ( I believe there was an extended service bulletin on 01-02's but mine is well past 10 years old now) and I had to gut it and weld it back on "for now"; but I live in NY and need it fixed ASAP to pass emissions inspection. Is this a good excuse to go the performance route with a bigger downpipe and high flow cat? Or should I go with a stock type replacement? I dont want to have to worry about CEL's and looking for the best fitment, quality build, and easy installation option. Thoughts?
 


For a fast and sure fit with no hassle, I'd get a salvage downpipe assembly if available. And new gaskets. Be prepared for broken bolts at the cat-back flange (have drill and extra bolt / nut handy). Go soak the flanges in penetrating oil now and give yourself a sporting chance of not breaking!
 


FYI a catalytic converter heats up to do its job, and depends on a certain amount of exhaust flow to get hot enough to react.

If you use an oversize catalytic converter, it may never get hot enough and won't control emissions and could eventually clog because it's not "burning" off the residual HC's. A converter that's too small could also get too hot, but I don't know anyone who is going to try to put an undersized converter.

Be prudent in selection of any non-OEM catalytic converter if you have to pass emissions (and can't just disable the rear O2).
 
Anyone ever use this Eastern Catalytic converter?
http://www.rockauto.com/catalog/moreinfo.php?pk=1317548&cc=1382532&jnid=428&jpid=2

Seems to be one of the closest to stock I can find for aftermarket. Ideally, I'd like to get the set up with the best performance; but also have it not throw a code. I realize this is a fine line and it seems high-flow is impossible to guarantee. Another question: will most of these aftermarket products such as the eastern listed above eliminated the stock "U bend"? It's hard to tell from the photos; but I'm also no exahust expert so i'm not 100% on what I'm looking at.












5 If so, would this improve performance simply by removing that constriction?
 
idrivejunk said:
For a fast and sure fit with no hassle, I'd get a salvage downpipe assembly if available. And new gaskets. Be prepared for broken bolts at the cat-back flange (have drill and extra bolt / nut handy). Go soak the flanges in penetrating oil now and give yourself a sporting chance of not breaking!
Click to expand...

I'm already planning on putting new bolts and nuts on that; mine is pretty rotted away...
 
Do you guys recommend replacing the O2 sensors too when replacing a cat? nothing appears to be wrong with mine; but they are almost 14 years old
 


you should replace them both. a bad O2 sensor doesn't always tell you it's bad by throwing a code. they can be the cause of lost fuel mileage. only buy acdelco sensors. amazon is as cheap as anywhere to get them.
 
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