Sdempsey18

I was wondering if anyone here has done a muffler delete and an x pipe that deletes the secondary cats. If so could you post a video. I have just a muffler delete right now but I want to make it a bit louder without doing headers.

robert miller

You do know you will get a check engine light on the car that will stay on all the time. It will not make the car much if any louder at all.

I have LT headers back car off and 3 inch mid pipe with Borla ATKA cat backs. To me if I was looking for more sound out of this add on it was 100% a waste of money for sure. All of this was not much better than the stock sound. Robert

Sdempsey18

The two rear cats in the stock OEM X pipe are unmonitored. A borla or corsa x pipe won't throw a cel 99% of the time.

eboggs_jkvl

Not totally correct my friend. He said secondary CATs. Those are not monitored by the O2 sensors and won't throw a code if they are removed when you put in a Borla or Corsa X pipe.

Elmer

lakemg

I suspect that Mr Miller is referring to the fact that the straight pipe muffler delete section will not have the AFM valves configured into the system and could indeed cause a CEL...

HorsePower Junkie

What is the purpose of deleting the secondary cats?

lakemg

Makes it louder

HorsePower Junkie

Is it just to get more sound out of it? Make it louder? Make it sound deeper?


Is there any performance gains to be had without the secondary cats?


Does the X-Pipe add any performance or is it more for more old school muscle car sound? Or does an X-Pipe make it sound more raspy?


Would just adding a piece of pipe to replace the secondary cats sound more old school muscle car like sound?
Any performance gains?





.

lakemg

Louder sound primarily.
It might make it a tad more raspy, but you're not going to make these cars sound like an old school muscle car with just an exhaust modification. I say this because I also own a 1969 Z/28 and even with the headers that I put on my C7, my C7 does not sound like my Z/28. Firing order and engine design keep them sounding differently. My Z/28 sounds better than my C7, but it doesn't run nearly as good as my C7
It would only increase output by a few horsepower, but nothing to write home about.
There are some youtube videos out there which will give you a feel for how it impacts the sound.

On edit: I need to also note that my Z/28 has headers and 50 series flowmasters, so I wasn't comparing my C7 with headers to a stock sounding Z/28.

VictorBarron

Corsa X Pipe with secondary cat deletes sounds terrific.

thejuice401

the corsa x pipe gets rid of the secondary cats?

thejuice401

looking to do my x pipe first, and if im not a fan i want the corsa xtreme exhaust also.

upcharger

X-pipe makes a difference. I bought a magnaflow exhaust system as well so my car is nasty loud. If I were to do it over Id delete secondary cats and run straight pipes. Save money, same effect. And I agree with Lakemg, I have a 75 caprice with a cammed 383 stroker with hedman headers and 50 series flows, caprice sounds better, but the z06 is supreme

JerryU

The OEM exhaust has an X pipe. In fact Vettes have used one for some years. The Borla "X Pipe" eliminates the secondary CATS.

Does that reduce the flow restriction enough to add much power? Probable some but also probably not noticeable.

Does it reduce restriction enough that the existing air/fuel map can't adjust under all conditions- probably not.

Does removing a CAT or getting a tune cause warranty problems-you bet!

If I wanted a more throaty sound I'd get Borla or Flowmaster mufflers designed for sound not just eliminating flow restriction like NPP!




OEM exhaust with X pipe and small CATs left, Borla removed CATs and X pipe center (Corsa, double X pipe without CATs right.)

joemessman

Yes.

eboggs_jkvl

I would add only 1 point of clarification.

Removing a monitored CAT will require a tune to stop throwing a code. Removing downstream secondary CATs should not throw a code.

Our cars have 4 CATs. The secondary CATs are not monitored. If I throw a code when I put on the Borla and remove the secondary CATs, I will take the Borla off, sell it, and go back to the stock X-Pipe.

Elmer

HorsePower Junkie

Elmer,

Did you get a chance to install your Borla x-pipe, and did it throw a code?


.

eboggs_jkvl

Seems my first try for the pipe hit a "supply" snag. I'm currently waiting on the delivery of the pipe. Then I need to get everything over to my friends house who has a 4 post to get the car up in the air and make this easier on my old back!

Elmer

HorsePower Junkie

robert miller

Elmer I know I put LT headers on the car with the 3 inch mid pipe with out the back cats on the car. But I do have all the valve's after the mid pipe on the car also have NPP Borla cat back. Now my check engine light stay's on all the time.

But now I am putting a A/A TI set up on the car and will be getting a tuner on it.