[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.

 

[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.

 

[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.

 

[BodhiBenz1987]

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.

On the Gen 2 you have to remove the little panel to access the drain plug and filter. Here is a photo of the setup when you get the access plate off, looking up through the opening. Looking at this photo now (it's older), you can actually see the DEF injector up there too, to add to the exhaust system photos.