Single factory to dual exhaust

2liter · June 6, 2020

Has anyone done this? If so what is your set up? Seems like most have the dual that are upgrading, haven’t found much on upgrading the single. 2020 LTZ 5.3

Bob Anderson Jr. · June 7, 2020

I don't have an answer. I have the same question. I've got a 2020 GMC SLE with the dual tips. Would like to have an actual dual exhaust, not just tips.

Konichiwa · June 7, 2020

I did it about 1 month ago. I ordered a corsa 21028 cat back kit, which at the time I purchased they had a $125 rebate so it was free shipping and a rebate. The dual corsa system matches up with the frame but I had to weld up my own exhaust hangers for the rear exits. The truck is also missing the driver's side heat shield for the spare tire but I opted to use titanium exhaust wrap off amazon which is far cheaper than the stock heat shield. The rear bumper actually has the cutouts for the chrome tips on true dual exhaust trucks but you would have to change out the bumper cover I believe and buy tips as well. The corsa system exits as a slight down angle so I felt that enough to clear the bumper and exit nicely. No need for tips, forcing my wallet to diet was taking its toll....you'll need 1/2 exhaust hangers which I got off ebay and the rubber exhaust hanger itself also off ebay.

Overall it turned out great, sounds great, with the GM cold air intake and thier recalibration, I swear the truck is a whole different animal now.

2liter · June 8, 2020

I just had the GM CAI installed Saturday, damn dealer didn't do the flash so I have to take it back. I ordered a dual rear exit Borla exhaust that the GM accessoies site said would work with my truck but the dealer said it didn't work. Looking at the Stainless works Legend double side exit but don't see many reviews on their exhaust so still up in the air between that Corsa 21030 or the Borla single touring.

Konichiwa · June 8, 2020

Did the dealer say why it wouldn't work? Length of bed? Crew cab or double cab? I have a double cab with a standard bed. They may also be saying it doesn't work because your rear bumper isn't configured for it. I took the chance with the dual rear knowing I was going to fabricate my own hangers so I could drop the exhaust lower than my bumper. If you know someone who can help you do that or if you're in Vegas I can help you out. Go with dual rear, you won't regret it.

Unknown_eyes · June 9, 2020

On 6/7/2020 at 3:15 PM, Konichiwa said:

I did it about 1 month ago. I ordered a corsa 21028 cat back kit, which at the time I purchased they had a $125 rebate so it was free shipping and a rebate. The dual corsa system matches up with the frame but I had to weld up my own exhaust hangers for the rear exits. The truck is also missing the driver's side heat shield for the spare tire but I opted to use titanium exhaust wrap off amazon which is far cheaper than the stock heat shield. The rear bumper actually has the cutouts for the chrome tips on true dual exhaust trucks but you would have to change out the bumper cover I believe and buy tips as well. The corsa system exits as a slight down angle so I felt that enough to clear the bumper and exit nicely. No need for tips, forcing my wallet to diet was taking its toll....you'll need 1/2 exhaust hangers which I got off ebay and the rubber exhaust hanger itself also off ebay.

Overall it turned out great, sounds great, with the GM cold air intake and thier recalibration, I swear the truck is a whole different animal now.

Do you have any pictures from the rear of the truck. I was thinking of doing the same and I'm curious what it looks like from the rear. I do worry about the heat from the exhaust traveling upwards into the bumper assembly and possibly damaging the parking sensors or plastic trim.

Konichiwa · June 10, 2020

2 hours ago, Unknown_eyes said:

Do you have any pictures from the rear of the truck. I was thinking of doing the same and I'm curious what it looks like from the rear. I do worry about the heat from the exhaust traveling upwards into the bumper assembly and possibly damaging the parking sensors or plastic trim.

Sorry I think my pictures are too big to upload. I hit the limit. PM me and I can send more. My truck doesn't have the parking sensors and I don't have any wiring above the exhaust. I'm not sure I'd it made a difference or not but I installed the factory GM 2" lift kit also.

Unknown_eyes · June 10, 2020

16 minutes ago, Konichiwa said:

Sorry I think my pictures are too big to upload. I hit the limit. PM me and I can send more. My truck doesn't have the parking sensors and I don't have any wiring above the exhaust. I'm not sure I'd it made a difference or not but I installed the factory GM 2" lift kit also.

Thank you. That's exactly what I was looking for. I like the look. I really want to swap out the bumper shell for the one with the cutouts and then do the exhaust. I just don't want to part with the money.

2liter · June 10, 2020

Stealership wanted $800 for the bumper

Konichiwa · June 10, 2020

3 minutes ago, 2liter said:

Stealership wanted $800 for the bumper

I wouldnt have thought any less.... and that's probably not even painted as well.

Check out gmpartsdirect or other gm part places.

The part number for an Elevation, probably all models with dual exhaust is 84574365 Rear Bumper Cover Primed $443.

That's a start, but then you'll have to buy the tips which are roughly $90 a piece, then have to have the exhaust welded into the tips which will require a stainless welder, and I'm not even sure those tips are stainless too. That's a lot of bending and sheetmetal work which I didn't want to hassle with even though i could do it. The cost of the cover and painting it wasn't worth the hassle to me. I used the money to pick up some lights for the front and lift kit, etc.... there's another thread here i just saw of a member posting his corsa rear system with a video and sound. Mine sounds exactly like that. No regrets at all. Next I'm cutting out that flattened pipe under the transmission and welding in a straight one. I've got the time that's for sure.

2liter · June 10, 2020

How is the sound in the cab. Have you towed anything with it on?

Konichiwa · June 10, 2020

Sounds great, in fact I want it even more rough. Wish it was more like an old school 350 with a cam and 4 barrel Holley. Never towed anything yet. Was going to this week but only a 22ft flat bed trailer to pick up 20' sticks of steel. This is my third corsa system all in trucks. Can't go wrong if you ask me. I really don't know what the dreaded drone sound is that members speak of. I changed my exhaust after 2 weeks of having the truck so maybe I missed it during that time. I think headers and a y-pipe will come later.

Carlos DavilaR · March 29, 2021

I have seen this question couple of times, about the towing with the upgrade dual exhaust. Could this be a problem? asking because I want to do this upgrade, an Im towing almost all the time

Diamond817 · April 3, 2021

Since swapping the bumper cover to the dual outlet bumper cover is so cost prohibitive, has anyone just reversed the exit offsets on the stock exhaust pipes and had the exhaust exit under the standard bumper? Seems like it would line up just right.

Diamond817 · April 3, 2021

On 6/9/2020 at 10:37 PM, Konichiwa said:

Sorry I think my pictures are too big to upload. I hit the limit. PM me and I can send more. My truck doesn't have the parking sensors and I don't have any wiring above the exhaust. I'm not sure I'd it made a difference or not but I installed the factory GM 2" lift kit also.

If you removed the offsets you could come straight out under the bumper and add tips, no?