jclemen

I have a set of DPs and x-pipe to install. I've read a lot of posts on exhaust review but looking for some detail on removing the stock exhaust. I've done a lot of exhaust work, if I can avoid paying someone I'd like to try this.

My main question is: Do you need to remove the rear underbody brace to remove the exhaust? I'm NOT using a lift unfortunately. The driver side pipe runs all the way from the downpipe to the resonator. Not sure if I'll have enough room to fish it out with the brace in place without using a lift. I'd rather not remove the entire undertray to get at the brace bolts if I don't have to. Anyone have any experience doing this? The passenger side pipe disconnects at the secondary so I'll remove that to help with the fishing...

Also wondering if folks are removing the o2 sensors prior to dropping the exhaust or simply unclipping the harness and removing the o2s off the car.

abcut973

I've not done it but i watched the guy who installed my hpipe.
Basically it will be a lot easier to use a lift. Then you could use a friend as second pair of hands it's helpful too.
What i think you can do is remove the downpipe (driver's side) + 2ndary cat (passenger's side) up to resonator at once. Then you will need to cut the resonator (passenger's side) and weld the x pipe to the catback. Remove the downpipe (passenger's side) and install your customized DPs. You'll have to go with straight midpipes up to the xpipe. You can use Vbands in order to have a bolt-on/off system.
Or do you want to install the x-pipe in place of the 2nd cat and keep the resonator? It might be easier this way.

See some pictures i found to illustrate. And i don't think you need to remove the rear brace. The resonator/catback (once detached from the midpipes) can be pushed further back to help with space. GL

jclemen

Cool, thanks for the feedback. I'm looking to keep the stock exhaust for later bolt-up (dealer visits) so i'd like to avoid cutting. Totally agree, the lift would be a big help.

I've got a set of gt-pro downpipes and x-pipe that are bolt on, install should be easy. I'm really just wondering about removing the stock exhaust with the clearance of the rear brace since it essentially has to come out in one piece.

abcut973

Well you can do it in 2 or 3 steps. See the picture of the exhaust on the floor? The separations are not cut but parts you can unbolt. Therefore you can remove the front part first: downpipe driver's side + 2nd cat then passenger's side downpipe. In the back you can remove driver's side muffler first then it will give you more flexibility removing the passenger's side muffler + resonator.
IMO you don't have to remove the OEM exhaust in one block (almost impossible).

jclemen

Sorry, when I said one piece I meant the driver side downpipe and secondary cats. The pass side downpipe will disconnect at the secondary cats which may allow some additional wiggle room. I'll be leaving the stock resonator and mufflers in place.

When I'm looking at the driver side downpipe at the front of the car, not much room to move it forward enough for the secondary cats to clear the brace.

I've got a good pic of the stock system from this link. The brace is in place but don't know if its in or out when dropping the driver side pipes.

https://mbworld.org/forums/c63-amg-w...-2010-c63.html

abcut973

I get your point. How about moving the downpipe backward to clear the front and then move/bend it forward to clear the brace .
If you look at the OEM exhaust in your link (post #1) it looks to me the driver's downpipe is cut.