X pipe
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,008
From: Texas
2) Technically "No" since it removes the OEM secondary cats. However, those cats are not monitored by the PCM so the car will still pass the OBD "plug in" test. The secondary cats are very difficult for an inspector to see if they're missing since they're above the tunnel plate. As such the cars usually pass visual as well. If you have an over-achiever that spots the secondary cats missing.....very unlikely....just reinstall the OEM pipe. It's a 30-60 minute swap.
Racer
Joined: Mar 2017
Posts: 297
Likes: 66
From: Coweta, OK
I went with the Speed Engineering Double X on my 19 Grand Sport. The stock NPP set up really wakes up with the secondary Cats removed. I got tons of compliments on the sound level. and still had zero drone.
I'm in the process of buying a 17 C7Z06 and will be doing the same X-pipe on this car.
I went with the Speed Engineering set up over the EOS set up because it is a one piece replacement versus a 2 piece set up. I dislike adding exhaust joints as they are a place that could potentially leak.
Link to set up:
Speed Engineering X-Pipe
I'm in the process of buying a 17 C7Z06 and will be doing the same X-pipe on this car.
I went with the Speed Engineering set up over the EOS set up because it is a one piece replacement versus a 2 piece set up. I dislike adding exhaust joints as they are a place that could potentially leak.
Link to set up:
Speed Engineering X-Pipe
Le Mans Master
Joined: Jun 2019
Posts: 5,408
Likes: 2,136
From: Loveland
If your information was complete, you can get better help.
I have the EOS, good price, works good, sounds good. It does add a little increase in sound but not stupid. As far as passing inspection, it depends where you live. In Colorado, not an issue.
I have the EOS, good price, works good, sounds good. It does add a little increase in sound but not stupid. As far as passing inspection, it depends where you live. In Colorado, not an issue.
Drifting
Joined: Apr 2022
Posts: 1,856
Likes: 792
From: Earth
I went with the Speed Engineering Double X on my 19 Grand Sport. The stock NPP set up really wakes up with the secondary Cats removed. I got tons of compliments on the sound level. and still had zero drone.
I'm in the process of buying a 17 C7Z06 and will be doing the same X-pipe on this car.
I went with the Speed Engineering set up over the EOS set up because it is a one piece replacement versus a 2 piece set up. I dislike adding exhaust joints as they are a place that could potentially leak.
Link to set up:
Speed Engineering X-Pipe
I'm in the process of buying a 17 C7Z06 and will be doing the same X-pipe on this car.
I went with the Speed Engineering set up over the EOS set up because it is a one piece replacement versus a 2 piece set up. I dislike adding exhaust joints as they are a place that could potentially leak.
Link to set up:
Speed Engineering X-Pipe
Racer
Joined: Nov 2013
Posts: 400
Likes: 269
The original ones were good and could be used but i didn't want to take chances, if they did leak then I would have to take everything apart again.
Drifting
Joined: Apr 2022
Posts: 1,856
Likes: 792
From: Earth
Drifting
Joined: Apr 2022
Posts: 1,856
Likes: 792
From: Earth
I went with the Speed Engineering Double X on my 19 Grand Sport. The stock NPP set up really wakes up with the secondary Cats removed. I got tons of compliments on the sound level. and still had zero drone.
I'm in the process of buying a 17 C7Z06 and will be doing the same X-pipe on this car.
I went with the Speed Engineering set up over the EOS set up because it is a one piece replacement versus a 2 piece set up. I dislike adding exhaust joints as they are a place that could potentially leak.
Link to set up:
Speed Engineering X-Pipe
I'm in the process of buying a 17 C7Z06 and will be doing the same X-pipe on this car.
I went with the Speed Engineering set up over the EOS set up because it is a one piece replacement versus a 2 piece set up. I dislike adding exhaust joints as they are a place that could potentially leak.
Link to set up:
Speed Engineering X-Pipe
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Racer
Joined: Mar 2017
Posts: 297
Likes: 66
From: Coweta, OK
Intermediate
Joined: Jun 2018
Posts: 48
Likes: 17
From: Brisbane CA
I live in California, so removing the secondary cats makes me nervous even if it's hard to see that they are missing.
Question: Are there any CA residents here who can share their experience with x-pipes and not having the secondary cats?
Another question: Will the NPP in Touring mode still make the exhaust quiet? (asking on behalf of my neighbors
)
Thanks!
Question: Are there any CA residents here who can share their experience with x-pipes and not having the secondary cats?
Another question: Will the NPP in Touring mode still make the exhaust quiet? (asking on behalf of my neighbors
)Thanks!
Racer
Joined: Mar 2017
Posts: 297
Likes: 66
From: Coweta, OK
my GS the X-pipe was a perfect change in sound. I actually wanted a little more noise but not enough to spend money on Mufflers.
I now have a 17 Z06 with the EXACT same mid pipe and it's noticeably louder and I have zero desire to spend money on a different exhaust set up. it's great the way it is now.
Stealth mode on the Z06 is still perfect for being quiet.
Thread Starter
Heel & Toe
Joined: Nov 2023
Posts: 20
Likes: 1
I went with the Speed Engineering Double X on my 19 Grand Sport. The stock NPP set up really wakes up with the secondary Cats removed. I got tons of compliments on the sound level. and still had zero drone.
I'm in the process of buying a 17 C7Z06 and will be doing the same X-pipe on this car.
I went with the Speed Engineering set up over the EOS set up because it is a one piece replacement versus a 2 piece set up. I dislike adding exhaust joints as they are a place that could potentially leak.
Link to set up:
Speed Engineering X-Pipe
I'm in the process of buying a 17 C7Z06 and will be doing the same X-pipe on this car.
I went with the Speed Engineering set up over the EOS set up because it is a one piece replacement versus a 2 piece set up. I dislike adding exhaust joints as they are a place that could potentially leak.
Link to set up:
Speed Engineering X-Pipe
Thread Starter
Heel & Toe
Joined: Nov 2023
Posts: 20
Likes: 1
Racer
Joined: Nov 2023
Posts: 427
Likes: 1,070
From: So Cal
2024 C7 of the Year Finalist - Unmodified
I live in California, so removing the secondary cats makes me nervous even if it's hard to see that they are missing.
Question: Are there any CA residents here who can share their experience with x-pipes and not having the secondary cats?
Another question: Will the NPP in Touring mode still make the exhaust quiet? (asking on behalf of my neighbors)
Thanks!
Question: Are there any CA residents here who can share their experience with x-pipes and not having the secondary cats?
Another question: Will the NPP in Touring mode still make the exhaust quiet? (asking on behalf of my neighbors
)Thanks!
Intermediate
Joined: Jun 2018
Posts: 48
Likes: 17
From: Brisbane CA
I'm going to check with a local speed shop that does custom / hot rod exhaust, see what they are willing to do.
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,008
From: Texas
There is no tailpipe sniff test for a C7 except in rare cases if multiple thousands of dollars have been spent at a certified repair facility to repair a car that still fails the OBD test.
The car will fail the visual inspection if the technician notices they're missing. This is difficult on a C7 since the secondary cats are hidden by the tunnel plate. Technically it is a Federal crime to remove cats but obviously it's not heavily enforced.
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,008
From: Texas
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,008
From: Texas
Have it shipped to a family member or friend outside of CA and then have them ship it to you.