Hey guys! About ready to go buy a cat now that I have some cash. What kind of converters are you using and which ones seem to be the best out there? I have the stock one on there and I'm ready for it to go. I've seen a few people using catco, are they anywhere as good as magnaflow?

Thanks everyone!
Happy New Year!

 

Anything but the crap GM put on there from the factory is going to be an improvement. If you can see through it (I've had a couple direct-fit replacements from the parts store), it's going to be fine. None of them are cheap.

 

I would get a non direct fit, i just did mine with direct fit and what a piece of S**T. #1 you loose about six inches of air flow with the direct fit.
#2 you will have to have it welded any way, because where the clamp is the 2.5 inch pipe will no longer be straight. Will probably have to have it cut off.
#3 Sense I have had mine changed I have had nothing but trouble with my car.
The place I bought it tried to talk me into one that could be welded without direct fit. I should have listened. So I will buy a non direct fit next time.

Direct fit> http://www.summitracing.com/parts/MPE-36636/



Non Direct fit> http://www.summitracing.com/search/P...ytic+converter

Oh by the way the OEM was a great CAT, mine lasted 22 years and I only changed it because i wanted a newer one.
Oh and don't forget you can get about $50 bucks for your old Cat, precious metals in them, platinum, and a few others. Ive seen them sell for $150 on feebay. anything from 89 and older.

 

1. No. ANYTHING is better than the stock pellet bed system that is in most of the stock thirdgen catalytic converters. These are highly restrictive and have a tendency to rust out the plug and let loose their pellets. Again, if you can see through it, it's an improvement.
2. If you got a tailpipe expander, you wouldn't have this issue. A chisel (hand or air) will slit the pipe on the old cat open so it can be slid off of the crossover pipe (and it's 2 1/4 pipe). Works on ANY exhaust slip-fit connection.
3. That generally means other issues, such as a clogged muffler (if just the cat was replaced)... And since you said you lost exhaust flow after replacing the cat, I would expect a clogged muffler. You should have gained flow.
4. There's a reason why the cats weren't welded in the first place... On ANY car.

 

Can that happen Maverick, the muffler be clogged? All I know is I am having some issues with my car that I did not have before changing out the cat. Really frustrating. I know you know way more than I do about cars, but i was told by 3 different mechanics that i choose wrong with the direct fit.

 

Yes, the guts in the converter break up and get passed downstream into the muffler by the exhaust gases, which clogs the muffler. If you were to install a pressure gauge somewhere along the line, you would probably find that the flow would improve when the muffler is disconnected from the system either by disconnecting the rear cat flange or the slip joint at the muffler itself. If your cat was "fine", why was it replaced? Generally, the cat is replaced only in cases of rust or the internal structure breaking up due to both chemical erosion (the chemicals in exhaust are corrosive just like rust) and mechanical vibration (railroad crossings, that enormous pothole, etc).

BTW, the metal coating on the glass beads/metal honeycomb is made of platinum, palladium, and rhodium, among other things. And yes, most performance cats are pretty much the same as the direct-fit, but with bigger holes in the honeycombs, which is still better than the stock pellet bed converters. Most high-flowing stock cats are made this way currently.

 

^ mine wasn't the pellet kind, was a small straight shot honey comb that fell out, but have thought about putting one back on, good mileage, runs great, bad bad stinky exhaust like a badly adjusted kerosen lamp.

found several hi flow cats for cheap on ebay, less then folks says its worth scrap???

 

And in CA the cat might cost more than the car!! I think now every new cat needs a CARB number and can only be sold to and installed by an approved shop and can only be welded and the number is tracked. I could be wrong. It was too depressing to read all the details. But it sounds about right for the new California.

 

^ lot of them say a shop will not install it in CA but you can go out of state or DIY and it will pass smog for 96 and under.

 

I think it may pass the sniffer but if they see a 'new' cat it has to have the CARB number stamped on it. Got to try to make it look really old.