E55 Custom exhaust or muffler/cat removal

[Swift1092]

Hey guys is the cat pipe on my e55 exhaust removable or is it all one pipe??
Ive seen a few on YouTube with muffler/cat removed and they sound pritty awesome is there any kits to do this or is it a full exaust system? Tha ks in advance

 

[daveenty]

Usually either a cut and gut or cut and replace with straight pipe.

Either way would involve some welding.

 

[Swift1092]

Is it pricey?? What is removed? Just the cat?

 

[AMGeed]

Usual method is to remove the secondary cat on each bank along with the resonator. This filled in with a x-pipe. Depending on where you have it done, anything from £350 - £500 and 3hrs work.
Mine looked like this when finished.

As Dave above says, you can gut the cat if you prefer and reweld. Less chance of falling foul come MOT time although mine sailed through minus cats. This method is probably cheaper too.

 

[Swift1092]

Will removing the primary cats internals and mufflers cause ecu faults and engine management lights and problems??

 

[John]

Despite the possibility of it doing so - it doesn't on mine...

I think you can get issues on W212s doing it though.

 

[daveenty]

Should be OK on the 55. Don't they have 2 cats per side anyhow? It's usually just the secondary cats which get removed, so shouldn't have any issues with CEL or MoT.

I had to have the O2 sensors mapped out on mine but, as John says above, mine's a W212 (Bi-Turbo) with only one cat per side and I took them out completely.

 

[Phil woods]

Was going to have mine decatted but was warned off by someone who experienced a strong fuel smell having done it on a 55 anyone run into these issues or did he have a rich tune?

 

[Mat B]

The strong fuel smell is from the lack of cats.
I don't run any cats at all and she purrs like a kitten. Faultless.

 

[Phil woods]

The strong fuel smell is from the lack of cats.
I don't run any cats at all and she purrs like a kitten. Faultless.

And how bad is the smell 1-10 10 being the worst

 

[Mat B]

Its very strong with no cats at all. About a 6 or 7.
When I just had 200 cell racing cats a 1 or 2

 

[Phil woods]

Its very strong with no cats at all. About a 6 or 7.
When I just had 200 cell racing cats a 1 or 2

Thanks Mat that's just confirmed what I'd been told,not for me I'm afraid

 

[Swift1092]

Mines a w211, just wana be sure before i butcher the exaust and if i doo get faults will ave to fork out for a whole new system

 

[Mat B]

You won't get faults. It's a very common thing to do on the w211 e55.
If you look on my member gallery you can see where I have done and tried most exhaust mods.

 

[John]

Should be OK on the 55. Don't they have 2 cats per side anyhow? It's usually just the secondary cats which get removed, so shouldn't have any issues with CEL or MoT.

Yes, primaries and secondaries.

Just to clarify, the exhaust picture above is where the secondary CATs normally go.

Just removing these does not change the smell of the car.

If you remove the primaries as well, for example if you want different headers, the car will smell richer than before.

It's subjective but mine was worse with the original Bosch IC pump on the car.

It is much improved with an uprated pump although it does still smell richer - but I don't think it is that bad.

 

[kalvin928]

hi guys
when I initially purchased the car it was totally de-catted.... I only noticed the smell/ fumes when on the motorway with window down and it was strong... have now primary cats in but as now getting new headers fitted will be getting primary cats remove yet again.... however will see how it is and then may well opt for sports cats at end of the year...

 

[kalvin928]

Its very strong with no cats at all. About a 6 or 7.
When I just had 200 cell racing cats a 1 or 2

matt
have you now removed the sports cats? I know you had engine reconditioned/ enlarged was it because of this in anyway?