So I pulled the cats and my car now sounds like crap, what should I do

[darkostoj]

well I spent the last 4 days pulling the cats and installing the woodhouse poly engine mounts. Just started it up and even though it sounds great at idle, it now sounds aweful when you are driving around under acceleration, and it is much too loud now with a drone.

I have stock manifolds, no cats, and a corsa 3" catback... I loved how it sounded when the cats were on it, but I don't want the cats due to the heat, and have a hard time spending a lot of money they are asking for the hi flow cats...with the possibility of them still sounding like butt. I'm just really bummed since these were NOT easy mods since everything that could have went wrong did...I just want to be done with it and have my car have all the perf gains of no cats, sound good, and not have any side sill heat.

Also are people with woodhouse mounts experiencing vibration? I'm not sure if maybe there is a part of the exhaust hitting somewhere, but i am getting vibes at low RPM that I can feel in the whole car...its worse when the car is in gear and expecially when taking off in first.

 

[DVSGTS]

That's the nature of the poly mounts. It's going to transmit more vibration because the connection between motor and frame is alot more solid. You wont notice it as much in a couple of months. Not sure if the poly "breaks in" a little or if its just a simple mind effect.

You might be able to fit in another type of muffler where the cats were. As long as they are considerably cheaper than a high flow cat?????

 

[ViperTony]

Do what others have done. Cut the stock cats in half. Weld on the outlets cut to a 3" opening to fit your Corsa. The only expense besides your time would be welding which is cheap if you can find a local muffler shop with a good welder. Or do it yourself.

Vibration from the Woodhouse mounts goes away after a short period of time. It's normal.

 

[KNG SNKE]

Glad I found this thread. I have stock manifolds, Corsa 3 inch and my cats are coming off soon.

 

[Alexarz]

I have the Corsa and cats removed with cherry bombs in their place. It sounds great and adds horsepower and torque. Orlando in Kissimmee did the work. He has a monster turbo Viper and knew how to hook my car up.

 

[KNG SNKE]

I have the Corsa and cats removed with cherry bombs in their place. It sounds great and adds horsepower and torque. Orlando in Kissimmee did the work. He has a monster turbo Viper and knew how to hook my car up.

This on a Gen 2?

 

[martyb]

I have factory manifolds, no cats, and Bellanger exhaust and I love it. Sounds like a Lambo, nothing like my Gen 1 did.

 

[V10SpeedLuvr]

You can put mufflers in the place of the cats. I did this on Saturday and my car sounds much throatier now and the horrible noise it made when shifting gears is gone. I went with Moroso Spiral-flow mufflers. They were $50/each at Summit. I also have Borla headers. I still get some popping on decel, but not nearly as bad. I am way happier with this setup vs. my old "straight pipe" setup.

 

[Alexarz]

This on a Gen 2?

Yes, a 2000 GTS.

 

[Chuck 98 RT/10]

How much are 3" cats going for?

 

[dave6666]

How much are 3" cats going for?

I paid $329 for mine from Parts Rack. Really amazes me that kind of scratch makes for a deterrent to a proven performance mod that also cools your ass off.

 

[GoCanes1]

I have a set of stock Gen 2 cats sitting in my garage. Someone make me an offer.

Mike

 

[97snk]

I m getting some work done on my car and had them cut the cats out today, I was going to run straight pipe with corsa 3 inch exhaust but after reading this I might go the muffler route. Thanks guys!

 

[darkostoj]

I have a set of stock Gen 2 cats sitting in my garage. Someone make me an offer.

Mike

could you pm me how much you would want shipped to 48017?

 

[GoCanes1]

could you pm me how much you would want shipped to 48017?

PM sent.

Mike

 

[Canyon707]

I had the same issue with to much noise. RT Cats and Corsa Some like it some don't. I didn't care for the noise. I took of the cats and welded a reducer from the 3" corsa to the stock cats. It was a pain but, for me better with just Corsa.

 

[darkostoj]

might as well throw in a pic

and yes....those rear ramps didnt even come close to fitting haha

You must be registered for see images

 

[darkostoj]

alright i took it out for a real long drive (no side sills either haha) and i guess its still not optimal, but it will do for now. Idle sounds great, WOT sounds nasty, decel sounds real nice with no popping, its just that part throttle acceleration sounds awful and i got a nasty drone. I plan on hopefully doing turbo's this winter so i'll keep it the way it is for now and see how it does at the track in a couple of days.

the mounts even though are starting to vibe a little less, they are still pretty rough...i LOVE the tightness of how the car feels now, but hopefully after a while the vibes go away.

the funniest thing is that I had a pretty strong exhaust smell after going WOT with the stock cats...and once removing them its gone now...

 

[dave6666]

the mounts even though are starting to vibe a little less, they are still pretty rough...i LOVE the tightness of how the car feels now, but hopefully after a while the vibes go away.

the funniest thing is that I had a pretty strong exhaust smell after going WOT with the stock cats...and once removing them its gone now...

As has been said over and over on the Woodhouse mounts, they do settle down and drop to about 1/4 of the vibration after a while.

The exhaust smell gone away? You probably fixed a leak when you redid everything. I had the same problem with my GTS w/ stock cats and a Corsa cat-back. Stank like hell with the winders down at WOT. When I replaced all of that clamped mess with my fully welded side exhaust, no more stink with the winders down.

 

[darkostoj]

As has been said over and over on the Woodhouse mounts, they do settle down and drop to about 1/4 of the vibration after a while.

The exhaust smell gone away? You probably fixed a leak when you redid everything. I had the same problem with my GTS w/ stock cats and a Corsa cat-back. Stank like hell with the winders down at WOT. When I replaced all of that clamped mess with my fully welded side exhaust, no more stink with the winders down.

yea i didnt even weld anything up, its still all clamped together...but the stink is gone!

after doing a lot of searching it seems like most people with stock headers, no cats, and a corsa 3" catback don't really like the way it sounds.

 

[white out]

Would '99-'02 oe headers/manifolds help with the tone?

Have you thought about putting resonators in? They are a great way to kill drone.

Nick

 

[Paul Hawker]

Another option is just to run a single cat. Much cooler, but much less drone.

 

[dave6666]

Another option is just to run a single cat. Much cooler, but much less drone.

Um. Like on just one side of the car and not the other? Or not 2 pair in series? Which I've never heard of on a GTS. Double cattin'?

Confused in

 

[dave6666]

yea i didnt even weld anything up, its still all clamped together...but the stink is gone!

Well, maybe you just do stellar work!

Go reward yourself with an adult beverage!

 

[Trailertrash]

I have a gen 2 with stock manifolds down to a 3" flex braided section from summit then to 3" tubing I bent myself. Then I run the Moroso Spiral flow muffler under the side sills and again in place of the factory muffler in the rear. Total of two mufflers each side. Sounds awsome at under $200 for all 4 mufflers. HP and Torque figures are great also. Although mine is not stock HP numbers are 545HP and 560 TQ Trying to get to 600 on pump gas NA motor. and still achieve 23 MPG on the highway. Wish me luck

 

[sirhc76]

Ive got a set of 2.5 inch roe high flows that I cut out a few months back. Let me know if you want them they are taking up space in the garage.

Not to hijack your thread but it seems like several people are going with the moroso spiral flows which was a muffler I was considering. I went with 3x12 inch dynomax 24222 mufflers from summit. Anyone have a sound clip of the Morosos?

 

[RTTTTed]

I love my 3" Corsa track exhaust, no cats and 1 3/4" headers. Cruise is really quiet under 2,000rpm. The sound, when cruisin', is quieter than the Roe Hi-flows, stock Gen 2 headers and Random Tech catback.

I also have a set of stock '01 Headers, 90 degree bend and flex pipe and about 3,000mi. for sale. Also a set of Belanger 5>2>1 Headers with the pickles removed that are near new.

Ted

 

[thebigsnake]

Put them back. That's what I did.
The on board computer will be happier too.

 

[TAXIMAN1]

Do yourself a favor... Pickup the phone, and call JonB. GO with Random Techs 3' Ceramics..... They are very reasonable. And WELL worth it.. Your car will sound and run cooler and better.. I tried everything.... And my goals were the exact same as yours. Reduce Heat, keep noise level to a manageable level.

I don't understand how any of you guys run without Cats... I drove my 2001 without Cats for all of 5 miles, before I ordered high flows. And had the very same shop cut off all the weld work they had just done the weekend before, and put on the High Flows... The car sounded AWESOME when it was finished!!

My car sounded AND ran terrible, And felt weaker without the Cats.

 

[crviper]

So what about us Gen 1s? Would it be the same or better off that we cut off the cats entirely? Cause welding another muffler behind the other seems crammed up. I was going to remove my cats and muffler and have a cherry bomb installed.. Would that work or be WAY Too loud? I can only assume that there might be a difference in dealing with the side exhaust setup than second gen rear exhaust.