Does anyone have cat back Corsa exhaust on Tahoe? Recently purchased 2018 Tahoe with Corsa exhaust installed. Sounds great 95% of time. When going 45mph (very noticeable at 75mph plus) and removing foot from accelerator I get a loud grumble/rattle sound for about 4-5 seconds unless I accelerate again. It’s not when it drops to 4cyl from 8cyl. Thank you in advance for any input!
Corsa Exhaust
- Thread starter Zjazz1010
- Start date
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
Pivot
Full Access Member
- Joined
- Jul 2, 2017
- Posts
- 197
- Reaction score
- 134
Corsa here on a 6.2 with AFM disabled. Not sure what your noise is but I’m curious..
get under the truck with a rubber mallet and start tapping around, could be a loose heatshield, check around transmission, catalytic converters, around the driveline by gas tank and around the spare tire area, if you hit on the exhaust pipe in various spots you should be able to hear it "IF" that's what it is.
it could also be something inside a cat or inside the muffler.
It’s bizarre, done all you suggested already. It’s literally only around 2000 RPM during deceleration, for about 5-7 seconds….if I touch gas at all, it stops immediately!
It’s a loud sound similar to the sound of air brakes on semi but coming from what I believe to be the muffler. Sounds great 95% of time….only at approximately 2000 rpm on deceleration does it make noise 5-7 seconds, if I touch gas at all, it stops! I can get on it, cruise at any speed and everything is fine! Bizarre!
do you have the flap wired open? if not that might be what it is then unless you deleted it when the exhaust was changed
if not then I would take it by a muffler shop (specifically) because that is all they do all day long and ask if they can figure it out, probably wouldn't charge you much $20 bill or something.
Flap wired open? Lost me there! I bought Tahoe used and previous owner had exhaust done. Im going to take by muffler shop as you suggested because it’s driving me cRaZy! Thanks for suggestions!
ya starting in 2015 there is a factory "flap" that they added in the exhaust pipe so when it goes into 4cyl mode then it doesn't make it sound like a lawnmower engine, they also changed the location at some point, I think it was before the muffler then they put it after the muffler or something to that affect, if you do not see a spring and mechanism on the pipe before or after the muffler then it was deleted already. It would look something like this
Great info, thanks! I do not see anything of that sort, but lawnmower reference helps as well because that’s exactly what it sounds like!
could be the cyl deactivation mode you are hearing, the computer showing it on the DIC is slow, try putting it in manual 5 and see if it still does it, I think that disables dfm but could be wrong.
