I'm getting the Dynomax Super Turbo Catback (2 1/2") n figured I'd get a new catalytic converter too since mine is gutted after it got clogged a few months ago. Can someone recomend a good, high-flowing/performance cat to go with my new catback (that doesnt cost a fortune)?

IMHO keep it gutted and don't get a new one.

I got a Catco 4115 from summit with my dynomax super turbo 2 1/2 inch catback.

Nothing personal jandl, but it surprises me how many guys are fine with a gutted or removed catalytic converter. You guys need to take a trip to just about any major city in the world outside the U.S., and snort up a few lungfuls of good ol' pre-cat smog. The kind where you wake up every morning feeling like puking into your pillow from the stench and physical irritations caused by that wonderful brownish-yellow fog of vehicle exhausts. Bogota and Seoul are a couple of real good examples. There are lots more, many closer to home.

We've got it pretty good in the USA right now, thanks to catalytic converters, but it could get a whole lot worse, even in your town, because of all the 'don't know or don't care' jerk off, second and third world governments trashing the environment. I'd like to think that any of us in this country are smarter than that. Just because your city or county doesn't sniff cars for emissions annually doesn't mean that converter isn't doing anything.

None of us should have a problem running a converter. If I lose a tenth, so be it. Face it men: Relatively few cars in this group are going to be hurt by a good flowing aftermarket cat, or will gain crap from taking their properly functioning stock cat off.

It's amazing, to me, how hybrid/electric cars are getting ready to take over because of ecological concerns, and some guys are still removing their catalytic converters for a possible extra pony.

Hope you like the way that Honda hybrid pins you into the seat, Jethro, because that's what's in all our futures if we don't wise up.

I feel a little better now.

I really don't think it matters that removing the cat, i ran my camaro a year without a cat. It sounds louder and thraoty just like the old muscle cars. Our cars dont really pollute that much without the cat. i found that my car was running just as clean without the cat. And i live right next to L.A. and i dont think i see a problem with running a car without a cat cause smog will always bad.

i think needed to say what i need to say!


i would say run a magnaflow highflow cat. cheap and long lasting!

It's funny. I changed out my exhaust from the cat back a couple of years ago, but drove around for a couple of days without anything but the converter. I thought it sounded about right. Seems to me like the best thing to do would be run a good cat, like the magnaflow, then a pipe out the back of the car. Forget the muffler. It might be too loud for some folks, but still quieter than the Harley crowd.

Yeah and people that live in LA breath in O2 so poluted it's brown, look up in the sky and you'll see why you don't notice a difference.

Really? Take your "clean" car for an etest without the cat and see how "clean" it really is! The cat's job is to burn the remaining unburned fuel and crap that has come through these ever so efficient internal combustion engines. They are on there because these motors cannot burn everything that goes in and that my friend is called pollution! On the origional post, run the largest (3") cat you can fit. the more substrate area the better flow.

If you have a dead-on tune, you can pass emissions without a cat. I've known people that have done it. Yes, with our cars and 350s. In fact, if I don't switch over to exhibition insurance, I'll be trying to pass next year without a cat.

I don't run a cat right now because the exhaust that I recently installed was welded up with a pipe in it before I bought the exhaust. I did have one installed for a long time until I swapped exhausts. Actually gave it to a friend to use on his bird now.

It was a direct-fit Catco 3" high-flow cat. I bought it on eBay for like $112. Fit perfectly, as it should have.

I'm not one to go out and ruin the environment. If my exhaust had needed a piece of pipe in that place, I would've re-installed the cat. I'm all for the high-flow cats because they don't kill power much at all, couple horses at the most. I drive my car very little these days though, so its not like I'm out there driving 15000 miles a year without a cat either.

Drive out north of LA on the PCH and look back. That's when you can really see that brown soupy cloud hovering over the city and drifting out over the Pacific. Breathtaking! (literally) You guys who live out there already know this, of course.

Anyway, enough imagery.

Is the original cat on my 89 TPI 305 car a honeycomb or pellet type? If it's the honeycomb type, will I gain anything from the Magnaflow direct fit replacement job? I'll be putting my headers on as soon as Hooker sends me my spanking new y-pipe and it'll be a good time to put a new cat on if it'll make a difference.

Of course I'll likely tear my stocker up getting it off that awful original y-pipe anyway.

Thanks in advance.

Nobody is forcing you to live out there ?

the smog in l.a. is a lot better than it was 5-10 years ago... the air is pretty good especially in winter. its our ocean water that's dirty as hell.

I'd say get a Magnaflow or Catco. You can get one on eBay for about $50-100.

You guys with the V8's must not understand how ****ty our V6's sound without a cat. Not only does it sound like a little riceburner above 3000RPM's, it didn't really make much of a difference (if at all) in power when I cut mine out. The only reason I did it is because mine was bad and I didn't have money for a new or hi-flow one. Right now I'm saving for a hi-flow cat and a cat-back.

I would get the catco... but just to let you know that dynomax setup blows IMO.... and its gotta be put on a lift and have the axle hang to put it in because it's 1 piece from the cat to the muffler.

I had it on my last camaro... its just as quiet, if not quieter then stock. Only thing you pay for is mandrel bends.

I'm not a "tree-hugger" by any means, but I do understand taking care of what you have and this is our only planet. In any case, the high-flowing cats of today are just about as good as a straight pipe and probably flow better than a hollowed-out cat due to the turbulence created by the odd shape. If you want to remove the cat for flow reasons and hollow it out, you're not making much sense -- at least replace it with a straight pipe...and most performance car oriented people need not be complaining about cat flow unless the rest of the system is up to par. I find it amusing how many people cry about how restrictive these good aftermarket cats are when they're still running stock cast manifolds.