Ditching the cat

**Sweep** · Tuesday 9th June 2015, 13:39

The cat needs to go! What's the best way to go about it? Cut it out and weld a piece in or flange it? I'm on a Jetex cat back anyway so will it make it much louder?

Ben.

**Doingitsideways** · Tuesday 9th June 2015, 15:10

Better to flange it if you can.
That way, if you decided to return the car to road condition, you could stick a cat on it quickly and easily.

As for making it louder, it will a little, mainly because of the lack of restriction.

**Sweep** · Wednesday 10th June 2015, 07:48

Righto mate I think that's the way to go.

I'm hoping it'll free up some more ponies too!

**Santa** · Wednesday 10th June 2015, 08:10

Just a note, this is all obviously for non-road use.

**Doingitsideways** · Wednesday 10th June 2015, 08:28

Of course

**Sweep** · Wednesday 10th June 2015, 13:33

Of course, I would never condone the use of such things on our country's roads.

**Mr Sheen** · Thursday 11th June 2015, 13:27

Mine got noisier inside around the 50-55 mph, after ditching the cat.

**xllifts850** · Sunday 14th June 2015, 13:04

How do you get around the lambda issue? Have often thought about decatting but been put off by the lambda and emissions.

**ExternalError** · Sunday 14th June 2015, 13:13

by either putting a right angles spacer on the lamda sensor or mapping out the rear lamda sensor

**Sweep** · Monday 15th June 2015, 10:03

Originally Posted by xllifts850

How do you get around the lambda issue? Have often thought about decatting but been put off by the lambda and emissions.

Hadn't thought about that, what will be the consequences of that?

**t5 pete** · Monday 15th June 2015, 10:06

With you having a 850 it sits pre cat so it won't be affected

**xllifts850** · Monday 15th June 2015, 13:24

Originally Posted by t5 pete

With you having a 850 it sits pre cat so it won't be affected

Am I being dumb (probably lol) but my 850T5 has lambda at front and has cat, How does that work on my one, reason I ask is my lambda light is on at present and may as well decat when trying to reset fault.

**weagie** · Wednesday 17th June 2015, 16:35

As far as I've been led to believe if a car is fitted with a cat from the factory then it must have one at the point of the MOT test or it's an instant fail. It's one of the reasons mine failed lol

**jamesy12345** · Wednesday 17th June 2015, 17:10

A 100 cell/race cat would still get you through the MOT including emissions assuming the car is in good nick, without losing too much power

Emissions limits just for interest (out of date but still correct numbers I think):

https://www.gov.uk/government/upload...th_edition.pdf

**Jamest5r** · Wednesday 17th June 2015, 18:16

Originally Posted by xllifts850

Am I being dumb (probably lol) but my 850T5 has lambda at front and has cat, How does that work on my one, reason I ask is my lambda light is on at present and may as well decat when trying to reset fault.

Your lambda light being on probably has nothing to do with your cat 99% percent of the time, it could be as simple as a minor air leak somewhere, get the codes read if you can, also if your going for a decat and your cat is fine make sure they flange the pipe in and not permently weld it that way you can replace it for the mot.