Got a WRX 2002 bug eye, just put 2nd and 3rd decat pipe on aswell as back box, just wodering whats best to do with front pipe, 100 cell cat or decat??????

 

Are you bothered about adding the centre cat at MOT time or do you know a friendly MOT station? If no to the first or yes to the second, go decat. If your answer is yes and no then go 100 cell. Bob

 

Couldn't put it any better myself, so I won't

 

Isnt there a claim a little back pressure is better for the twin scrolls?

 

I have decat up pipe & decat centre/mid section & H&S 100 cell down pipe. You only lose 2bhp over a decat & it sails through the MOT. Talk of an increase in the number of roadside emission tests & the dwindling supply of friendly garages made my choice easy.

 

Cheers bob, my fella knows of a friendly little station that usually help me out with emissions when it comes to MOT time, so I think i will go for a full decat system before i go for the remap.

 

Keep the centre cat, incase you need if MOT time. Bob

 

Same here matey. Same here.

Hence why I went for a RCM sports cat.

Steve

 

I'm with the sport cat d/p. I have the prodrive one which is 100 cel. Ok, a decat is marginally better, but not enough to make a difference. Mot time it passes and when the police do a road side checks it passes. The full decat has had it's time because they're getting really strict with this now.

 

Strict? I am still waiting to meet someone who has had an emissions test at the road side. I did speak to someone on a forum from London once who it happened to but other than that...

There are loads of friendly MOT testers up North still. Emissions test is regularly accepted to be a mockery of a farce with everyone I have ever dealt with. Go decat, get your moneys worth out of your green/road tax.

 

Why risk it for a 2% increases in power. Or am I a soft southern environmentalist?

 

depends on the car surely as to whether it's 2% or not, if you're up in the mid 300s already I've seen people get another 10-20hp.

I've just bought a decat for this very reason!

 

Personally I'd go de-cat...but then again I do live in the north east where the majority of testers will give you a ticket as long as you say you fitted the de-cat AFTER the test

 

Just to clarify H&S state that "You only lose 2bhp" Not 2%. You can lose more than 2bhp on a hot day when ambient air temps raise your intake temps. So it's a pretty insignificant loss over a decat downpipe.

 

you mean the makers of fairly pricey sports cats say that .....

 

Good point. But then every manufacturing company runs as close to the wind on trade descriptions as they legally can .

And we all know Sudso washes whiter & better @ low temps than Fabribrite. Or do we?

 

I went for the Sports CAT personally (Prodrive). Couldn't bothered with the hassle at MOT time etc.

 

It would be interesting to see a comparision of decat d/p and 100 cel sports cat d/p on the same car. There has to be some gain, but how much exactly?

If it is only marginal (300bhp vs 315bhp) then real world you're not going to notice the difference unless you're chasing figures.

 

so what would happen if you come across a traffic policeman who has loads of experience and has knowledge of decat pipes etc....im assuming you'd end up getting a pg9 slip to rectify the problem making it more of a hassle to sort out

 

I was also concerned about the insurance implications. A decat car would be an MOT fail on emissions, therefore, technically, you've been driving an un-roadworthy car, thus insurance folks could -in theory- say "Insurance void"

Admittedly, I've yet to hear of this happening, but I wouldn't want to risk it, personally.

 

get a decat, i went the wrong route and got a ninja sports cat which was £300 and cat pipe for £100. ended up selling it and getting a hayward & scott decat which sounds much better and feels better. my MOT expires in december which i'm sure i can pass

wiley

 

Buy a good quality 100 cell cat. It doesn't affect performance much at all. I had a Saab 900 with 421 bhp using a 100 cell Kemira race catalyst.

I hate the smell of decatted exhaust fumes so I'm going to weld on a cat on my car which I bought with a decat pipe. Don't feel like switching downpipes everytime I have "MOT" eighter.

 

Been thinking the same thing when the time comes.. One thing got me thinking was the cost of a high flow cat H&S £475+vat up against a decat H&S £170ish. hell of a difference, that could all help go towards the remap.

Ive used H&S as thats what i using now, top quality.
Currently im thinking decat, and find a friendly MOT station (prob not hard)

 

i got pulled over and spot checked by vosa/police....they checked emissions, tyres, under the bonnet, under the car and they made me take the tints off my front door windows before they would let me go.


get a 100 cell cat and stay legal, VOSA are doing more and more spot checks and these include emissions.....you fail and it the impound for the scooby

you gain very little between decat and 100 cell anyway.

 

AFAIK, failure to pass an MOT does not make the car unroadwothy in itself.
Failure to inform your insurance company would however render you liable of driving a vehiucle uninsured.

 

if your car fails an MOT then you car is NOT TO BE USED ON PUBLIC ROADS, or in short not road worthy.

 

and yet as long as you have a retest booked you can drive it between tests and even to the re-test

 

I've been thinking of doing the same thing, what differences have you noticed, more power?

thanks
Iain

 

The mot only says your car is road worthy the day they test it. You could brake a drop link the next day,meaning it would fail, would your insurance not payout for this too?
Do the police fine you, points, or just give you 7 days to get it sorted with an mot stations approval?

 

you are allowed to drive the car to the test center as long as a retest is booked.

all this information comes from a friend of mine who runs a MOT garage.