Cat-delete questions?

[Ben Ingraham]

2011 M3 DCT with Meischterschaft SS GT.
I have questions about going catless or HFC. I assume this will bring the CEL lights on, correct? Is there a ECU reflash for this? Who would be the most knowledgable? (Shop wise) Also, would I be correct that this voids the warranty?
Price is also a consideration but not a deal breaker. I'd rather do things once and not guess around. I am stationed in Hawaii and I'd prefer to do the work myself.
Thank you for the input in advance.

[swamp2]

Yes, after 10-50 miles or so you will have a permanent CEL for emissions. You can have it reset but it will always come right back.

You can get this programmed out. There are multiple vendors here on the forum who can do this. It is very unlikley any local shops will have this capability.

Neither removing the cats nor using special software can void your cars warranty. However, you could get into a battle about that with your dealer. Of course the cat removal is likely a state and/or federal crime...

The lowest price option for this on the hardware side is something like Turner Test pipes. There may be imitators with a similar product but they are probably only a bit less expensive. Unfortunately the software is not cheap. Installing TTPs is a DIY type of job.

[e46m3to135i]

With BMW of Honolulu being the only dealer you and everyone else on the island can go to for warranty work. From my past experience, that dealer will look for ANY and I mean ANY reason to not cover something under warranty. Not trying to scare you but that dealer is the ONLY reason why I wont be getting test pipes/tune until I leave the island.

-Nick

[Ben Ingraham]

Ok, so from what I've read on this forum, I can install the Xpipe portion and get rid of the secondaries? I've heard that requires cutting. I've been under the car a few times. I cannot recall what that part of the exhaust looks like.

If I'm hitting on old post's, my apologies. I'm just trying to make sure I'm understanding what's been said.

[KmndntKlink]

don't get an xpipe, its a waste of time & money. 90% of the gains are from removing the primary cats (before the xpipe). Turner's pipes are great. it is NOT a DIY job unless you are experienced in exhaust work. It's supposed to be cut & clamp, so if you're comfortable doing that then go for it, but I took it to a shop.

test pipes will give you a CEL, removed with a tune from any of the vendors here. I recommend Mike Benvo @ BPMsport. Tunes are very expensive, but there's benefits beyond just removing the CEL. A tune will permanently remove the CEL light for emissions.

Depending on the xpipe you get, it can be a bolt on (no cutting). Challenge's street pipe seems to be the way to go for this route, but its 2 THOUSAND DOLLARS. Absolutely no way in hell is it worth that money.

Going catless won't void your warranty on your whole car. The warranty is only voided for parts you replace/if they can prove it caused damage to something else. So your exhaust warranty will be voided. But honestly, you're never going to have to RMA your exhaust. Tunes are completely transparent and no one @ the dealership will know (unless you tell them). Even then test pipes & a tune will not cause any problems with your car, so you'll be fine.

TLDR? get the test pipes & the bpm tune. you will not be sorry. Huge power & drivability improvements

[swamp2]

Originally Posted by Dashman

Removing primary catalysts can void warranty, secondaries are not O2 sensor pronged so they can't be blamed for engine faults.

Well we should separate law from practical issues here.

From the post above it sounds like BMW in Hawaii are hard asses and will TRY to void a warranty for anything. On the other end of the spectrum you have the Magnuson-Moss Warranty Act which the FTC stated makes it illegal for companies to void ones warranty based on the installation of aftermarket parts. In this case an aftermarket part could be a fully catless midsection. Again, yes the vehicle would not be legal for use on public roads (closed racing/road coarse would be fine), but a warranty can't be voided.

There is an exception to this rule in that if an aftermarket part can be proven (by the OEM) to be the cause of an EMISSIONS related warranty claim then the supplementary EMISSIONS related warranty on the car can be voided. I highly doubt that the warranty on the rest of the vehicle can be.