Decat

[Imola]

Hi all, was looking at getting a cat back exhaust system but missed flight home from recent holiday so thats a non starter :mad: at the moment :) . Think the wife and kids just wanted a couple of extra days away :D any way been advised to just replace the cats at a cost of £75.00 each which I thought was good, I will be able to re fit the cats before MOT when required. The guy said he wouldn't change anything else as he has done a few M5's and M3's and it does'nt half make a difference but also keeps the rasp note of the exhaust which I like. Any thoughts, searched but found nothing on this. Thanks

[peppernick]

just replace the cats at a cost of £75.00 each which I thought was good,
Are you replacing your existing kats with new kats or are you referring to bypassing them with straight through pipes? £75 seems rather cheap for a kat converter.

I take it your car is an E46 M3?

[Imola]

replacing cats with straight through pipes, cats can be bolted back in place if and when needed.

[Ade]

Hmmm, don't the M3's have a lambada sensor? Not sure where this would fit if the cats were completely replaced with a straight through pipe... Surely this would screw up the fueling?

Ade

[peppernick]

From what I know, the stock E46 M3 DME is able to handle kats up to 100 CEL, anything less (ie straight through pipes) the lack of back pressure may result in erratic running. However, this can be overcome with re-mapping. You'll get more power. Best person to speak to is Roy.

Also, the lambda probes that go into the exhaust piping before and after the kats come out together with the centre kat pipe work if you just unbolt them. You will need to weld new lambda probe mounts onto your new straight through pipes if you want to retain the bolt on/bolt off function.

If you just cut the centre pipes to remove the kats you can retain your stock lambda probe positions but that mean new pipes have to be welded on.

[Imola]

:confused: may have to have another chat with the guy, also by the looks of it need to ask him about my kats and not the feline type :o

[lee330sport]

The cats can be removed, but you will have a CEL light on the dash but no performance loss. For the 2 sensors, they can be connected and placed in a single mount on each of the pipes.

[Imola]

looks like I've got to ask the question about the sensors, not just as simple a I first thought although I was told it would take a couple of hours. cat or kat :confused: