[FlagrantBacon94]

Hello everyone. My first post on here. I was hoping to see if anyone has a gen2 diesel that they’ve deleted the muffler on. I’m looking at doing it to mine (I want to get that diesel sound out of it mainly). I’ve only ever seen or heard of the 1.4l gas models getting a muffler delete and they don’t sound bad, but I’d really like to hear about the diesel side of it if anyone has done it and if they recommend anything before actually doing it. I am currently waiting on my 100,000 mile warranty to finish but I’m only at ~32,000 miles. Eventually I’d like to do a full delete but that will be down the line. At that point I’ll just straight pipe it from the turbo and be done with it. But because of warranties I’m at a standstill. If anyone knows anything or finds anything that I somehow missed please let me know. Thanks in advance!

 

[MP81]

Do the Gen 2 diesels have a muffler? The Gen 1 diesels did not have one.

I wouldn't hold your breath on being able to delete - thus far, there has been no delete made available for the Gen 2 - and that was before the EPA crackdown that saw the Gen 1 deletes become extremely scarce (and expensive). Tuning would be a major issue in deleting the Gen 2 - it's proving extremely difficult to crack.

 

[BodhiBenz1987]

Do the Gen 2 diesels have a muffler? The Gen 1 diesels did not have one.

I wouldn't hold your breath on being able to delete - thus far, there has been no delete made available for the Gen 2 - and that was before the EPA crackdown that saw the Gen 1 deletes become extremely scarce (and expensive). Tuning would be a major issue in deleting the Gen 2 - it's proving extremely difficult to crack.

The Gen 2 has what looks like a resonator/muffler but is part of the SCR system. It might have a muffling effect but isn't really a muffler and couldn't be removed without the full "modification". I am guessing the DOC/DPF have enough muffling effect that it wouldn't make much difference to have a muffler downstream.

 

[Rivergoer]

Another approach...some here have reported switching to a Cold Air Intake (CAI) provides some added turbo sound and diesel rumble.

 

[FlagrantBacon94]

I had a good look under my vehicle when installing splash guards but didn’t really pay attention to anything but what I was doing. I know that the gen1 gas models had a massive muffler that ran down the middle of the vehicle. But I don’t think I remember seeing anything but just a regular pipe on mine when I had it off the ground.

Do the Gen 2 diesels have a muffler? The Gen 1 diesels did not have one.

I wouldn't hold your breath on being able to delete - thus far, there has been no delete made available for the Gen 2 - and that was before the EPA crackdown that saw the Gen 1 deletes become extremely scarce (and expensive). Tuning would be a major issue in deleting the Gen 2 - it's proving extremely difficult to crack.

 

[MP81]

I had a good look under my vehicle when installing splash guards but didn’t really pay attention to anything but what I was doing. I know that the gen1 gas models had a massive muffler that ran down the middle of the vehicle. But I don’t think I remember seeing anything but just a regular pipe on mine when I had it off the ground.

The Gen 2 has what looks like a resonator/muffler but is part of the SCR system. It might have a muffling effect but isn't really a muffler and couldn't be removed without the full "modification". I am guessing the DOC/DPF have enough muffling effect that it wouldn't make much difference to have a muffler downstream.

Okay, so it sounds like it's similar to the Gen 1s - SCR is the last piece of the exhaust, middle-ish of the car. Looks like a big resonator, but it's the SCR and definitely is needed on non-delete vehicles.

Another approach...some here have reported switching to a Cold Air Intake (CAI) provides some added turbo sound and diesel rumble.

You would be correct. The amount of turbo noise the car has (especially when you let off the throttle quickly) with a "CAI" (really more of a short-ram) is pretty crazy, but not surprising, given the turbo is like 8 inches away from the cone.

@Snipesy posted a good video of his with a K&N intake (it's the one on ours, I bought it off him, haha) on his 1st gen CTD:

 

[Snipesy]

I miss hearing the flutter

 

[Snipesy]

Don’t forget my VGT video which has an under hood mic for dramatic effect.

I highly doubt the gen 2 will sound that way but hey cool turbo noise.

 

[FlagrantBacon94]

So, I actually had to get under my car today because the oil drain door somehow decided it didn't want to stay connected to the entire panel. I did see what looked like a small muffler around where the cup holders would be. If this is actually a muffler I'm not 100% sure since I couldn't really get close enough to see everything there.

Do the Gen 2 diesels have a muffler? The Gen 1 diesels did not have one.

I wouldn't hold your breath on being able to delete - thus far, there has been no delete made available for the Gen 2 - and that was before the EPA crackdown that saw the Gen 1 deletes become extremely scarce (and expensive). Tuning would be a major issue in deleting the Gen 2 - it's proving extremely difficult to crack.

 

[FlagrantBacon94]

I miss hearing the flutter

Love hearing it on the modified trucks. happily the truck pull at the county fair this past year had a free truck pull event.

 

[MP81]

If you get a chance, can you snap a few pics of the exhaust system?

We have a really good thread that shows the entirety of the exhaust system (via a lift), not long after they came out, which has always been super helpful - but that is only for the Gen 1. Can't say we have anything similar to reference on the Gen 2s.

I'm expecting there to be no muffler, as GM doesn't have any mufflers on any of their other diesel products, since the turbo, DPF and SCR do such a good job of lower the exhaust decibel level.

 

[FlagrantBacon94]

If you get a chance, can you snap a few pics of the exhaust system?

We have a really good thread that shows the entirety of the exhaust system (via a lift), not long after they came out, which has always been super helpful - but that is only for the Gen 1. Can't say we have anything similar to reference on the Gen 2s.

I'm expecting there to be no muffler, as GM doesn't have any mufflers on any of their other diesel products, since the turbo, DPF and SCR do such a good job of lower the exhaust decibel level.

For sure. I'll grab some when I can and post the here.

 

[BodhiBenz1987]

If you get a chance, can you snap a few pics of the exhaust system?

We have a really good thread that shows the entirety of the exhaust system (via a lift), not long after they came out, which has always been super helpful - but that is only for the Gen 1. Can't say we have anything similar to reference on the Gen 2s.

I'm expecting there to be no muffler, as GM doesn't have any mufflers on any of their other diesel products, since the turbo, DPF and SCR do such a good job of lower the exhaust decibel level.

Here are a couple pics I took with the full pan off, that might be helpful. In hindsight I should have taken a couple of behind the engine too where the DEF injector is. The DPF can be seen in front of the engine, with the DOC out of site on top of the DPF (can be seen under the hood to the right of the turbo ... the DOC and DPF are combined in one unit. There are two EGT sensors in the DPF/DOC unit as well as the two thin tubes that attach to the rubber lines for the pressure differential sensor (you can see the tubes in the corner of the third photo). The NOx catalyst is the resonator looking things you can see at the middle of the car. The DEF injector is behind the engine and a little harder to see as it's fairly high up there. It is before the NOx catalyst. There is an NOx sensor in the tailpipe after the NOx catalyst. There is a particulate sensor just behind the flex pipe seen in the photo under the engine. And the third EGT sensor between the DPF and flex pipe. Unfortunately I didn't take clearer pics of the exhaust parts behind the car, maybe @FlagrantBacon94 could add those to round it out.

 

[BodhiBenz1987]

So, I actually had to get under my car today because the oil drain door somehow decided it didn't want to stay connected to the entire panel. I did see what looked like a small muffler around where the cup holders would be. If this is actually a muffler I'm not 100% sure since I couldn't really get close enough to see everything there.

That sounds like the NOx catalyst which is unfortunately a part of the emission system. The oil drain door on mine loves to come loose. And those screws are really hard to get "set" right. The concept of the access panel is great, makes oil changes really easy, but man, the design is a mess.

 

[MP81]

Don’t forget my VGT video which has an under hood mic for dramatic effect.

I highly doubt the gen 2 will sound that way but hey cool turbo noise.

I'm not sure it's much quieter inside the car, in all actuality, haha. It's loud. But in a good way. Usually.

The VGT definitely makes for some very interesting transitions, since it doesn't always need to use the wastegate, and doesn't really recirc - it just changes the blade angle. Makes for a lot more constant noise.

That said - the 1.6L does have a VGT, so it should sound pretty neat.

Here are a couple pics I took with the full pan off, that might be helpful. In hindsight I should have taken a couple of behind the engine too where the DEF injector is. The DPF can be seen in front of the engine, with the DOC out of site on top of the DPF (can be seen under the hood to the right of the turbo ... the DOC and DPF are combined in one unit. There are two EGT sensors in the DPF/DOC unit as well as the two thin tubes that attach to the rubber lines for the pressure differential sensor (you can see the tubes in the corner of the third photo). The NOx catalyst is the resonator looking things you can see at the middle of the car. The DEF injector is behind the engine and a little harder to see as it's fairly high up there. It is before the NOx catalyst. There is an NOx sensor in the tailpipe after the NOx catalyst. There is a particulate sensor just behind the flex pipe seen in the photo under the engine. And the third EGT sensor between the DPF and flex pipe. Unfortunately I didn't take clearer pics of the exhaust parts behind the car, maybe @FlagrantBacon94 could add those to round it out.

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Those are a great set of shots - yeah what I see there in the middle of the car looks similar to what we see under the Gen 1s. If there is no muffler out back (I think either the sedan and hatch mufflers are clearly visible underneath), then they went the same route as their other current diesels.

That sounds like the NOx catalyst which is unfortunately a part of the emission system. The oil drain door on mine loves to come loose. And those screws are really hard to get "set" right. The concept of the access panel is great, makes oil changes really easy, but man, the design is a mess.

Oil drain door for...the oil pan drain plug? Or to access the oil filter?

 

[Barry Allen]

At that point I’ll just straight pipe it from the turbo and be done with it.

If you remove every piece of exhaust treatment equipment (oxidation catalyst, DPF, and SCR catalyst) you will get all kinds of CELs as well as a 75 mile countdown for a defective emissions system that will cap your speed at 65mph, 55mph, 45mph, and then 4mph.

How do you plain to "straight pipe" a modern engine with all the emissions equipment?

 

[BodhiBenz1987]

Oil drain door for...the oil pan drain plug? Or to access the oil filter?

I meant the access panel on the underside panel held in by four screws ... I am not sure the term for the type of screw but I find it hard to get them to grab the tabs they supposed to go into.

 

[MP81]

Yeah - what is the access panel for? We don't get one of those on the 1st gen, but the drain plug is accessible without removing the under-engine cover. The oil filter is on the back lower passenger side of the 2.0L, sideways (cartridge-style), but it has a gutter that allows it to drain out a hole in the panel. Well, it does if it hasn't fallen off and onto your CV joint...ours is currently sitting in the basement after it did just that.

 

[FlagrantBacon94]

If you remove every piece of exhaust treatment equipment (oxidation catalyst, DPF, and SCR catalyst) you will get all kinds of CELs as well as a 75 mile countdown for a defective emissions system that will cap your speed at 65mph, 55mph, 45mph, and then 4mph.

How do you plain to "straight pipe" a modern engine with all the emissions equipment?

pickups do it all the time. if there is a kit, and i've heard there currently isn't right now, you'll need to mod the computer to thinking everything is still there. unfortunately it is illegal to do in the eyes of the EPA, but they're just money hungry turds that can suck an egg in my opinion. gen1 cruze had a fair delete kit that at least got rid of the exhaust components. i couldn't say for the EGR or anthing like that though.

 

[FlagrantBacon94]

Here are a couple pics I took with the full pan off, that might be helpful. In hindsight I should have taken a couple of behind the engine too where the DEF injector is. The DPF can be seen in front of the engine, with the DOC out of site on top of the DPF (can be seen under the hood to the right of the turbo ... the DOC and DPF are combined in one unit. There are two EGT sensors in the DPF/DOC unit as well as the two thin tubes that attach to the rubber lines for the pressure differential sensor (you can see the tubes in the corner of the third photo). The NOx catalyst is the resonator looking things you can see at the middle of the car. The DEF injector is behind the engine and a little harder to see as it's fairly high up there. It is before the NOx catalyst. There is an NOx sensor in the tailpipe after the NOx catalyst. There is a particulate sensor just behind the flex pipe seen in the photo under the engine. And the third EGT sensor between the DPF and flex pipe. Unfortunately I didn't take clearer pics of the exhaust parts behind the car, maybe @FlagrantBacon94 could add those to round it out.

I might actually be able to get my car in the air since my manager actually has his own garage and all. its just a matter or getting over there when he isn't busy and letting me use it for a few minutes.