Not sure if this should go in tuning section or not? I guess not as i'm "standardising"

I bought my coupe with no CAT and a decat pipe in place. I'm going to put the CAT in place for the first time in the next few days...

1. Is it really worth doing it?
2. MOT isn't until July
3. Only mod is a Fleamap
4. Will there be a noticeable performance drop?
5. Will the car run smoother?

Depends, reasons for doing it are on the spot vosa checks and failer of a MOT not to mention the fact that the car is simply not road legal and if you were to have a bump they would use it as a excuse not to honer your insurance.

Is it a normal turbo? if its not been rebuilt with the uprated oil seals then it really is just a matter of time before it fails way ahead of when it should.

The problem is that if its been mapped with a decat im not sure how putting a cat back on is likely to effect the map, you will feel a performance drop as the car cant get rid of the exhaust gasses as quickly as it could

You could consider a "race cat" instead, fit 'n' forget, best of both worlds...except that Milltek don't make 'em any more

i would say fit the cat again for the MOT and take it off again...."for your every day track day use"

i carried out a rolling road test before (with cat) and after (with de-cat)

no other changes to the car, same dyno, still the same tank of fuel, every thing was the same except the de-cat.

the results where interesting.

i gained 9bhp with a de-cat!

take from that what you will, but i think, great gain from a small cheap iteam!

(i have RR print outs to prove this!)

I have a 200 Mesh Powerflow race cat on my Stage 1 mapped Scottie (270bhp). Legal, and passed the MOT as well as improving the turbo response. I had the choice of a 100 mesh cat, but did not want to take the chance.....

200 mesh CAT on mine.

Had a de-cat on previous coupe and it was a pain having to change it over for MOT time, although it did improve performance and noise!

With the amount of those mobile VOSA check vehicles on the roads these days, personaly I wouldn't risk a de-cat as it would defo fail emissions test!

Anyone know what the punishment is for this kind of thing......just a fine or do you also get points?

It should run just as smooth as it does now, just a bit more muffled and restricted. It will make a noticeable difference to the sound, and a minimal one to the performance. I'd leave it off if the turbo has been fine without it for a while, it's down to your personal preference really.

The turbo has 360 bearing and uprated seals so it should be ok. Just think its not worth being caught as i don't "rely" on the cars performance, so i probably can't justify it.

How much are sport cats? ALOT i bet

I prefer to hear noise from the engine, not just exhaust. Would fuel consumption improve?

Interesting about the VOSA checks, wonder where I'd stand. Car should have a CAT but due to the engine being from an older vehicle means at MOT time it doesn't have the same emissions test so has never had one fitted...

But the requirements for emissions are based on the car's age, not the age of the engine?

I don't think that is true if its had a engine change and has been documented/ vosa inspected

Spot on.... the requirements are based on the registration date of the vehicle.

Not too bad, we supply and fit sports cats (FIA Appr race cats 100 cell,200 cell sports cats for £250 all in fitted. Its not a big deal really.

(that was not a plug by the way! or I would have posted this up on our traders section)

Do note, if it's got a mapping and you suddenly add a restriction to the exhaust, you might end up with detonation.

Obviously a sport CAT would be less restriction? So with the map on my car, this could be the better option.

That's much less than i thought they would be actually.

I'm assuming from previous comments a 200 cell CAT is safest?

100 cell SHOULD pass mot, 200 Cell much safer... put it this way, we have never had one fail yet... if it fails its your motor!

...should be no problem if properly warmed up, and these cats make a real difference to the performance (not cheap though).

I thought £250 was a bargain for a fitted sports cat!

Now that is a plug

Just a few questions;
Would you notice an improvement in performance on a standard car if fitted with a a sports cat?
Would you need a hybrid turbo to run a sports cat safely anyway ?
Would a standard ecu adjust to sports cat or would it need a re-map ?

Questions, questions.

Is it not cheaper to just put a standard cat on and get Flea to remap it?

Please note the most important thing.....
If your car is running a standard turbo (and it hasn't had the oil seals changed from the standard 270 degree to 360 degree ones, you will kill your turbo...
If it's had a fleamap, check with Flea the turbo's spec and have a chat with him...

Br
Will

With the cost of fuel to get to bristol and back, and having it remapped again i'd rather settle for the sport CAT

Still keeping the gains while being LEGAL

I meant try phoning or pm ing him to check what spec he had on it when it was mapped... Sports CAT is the safe option and compromise, butgive flea a call and see what turbo you're running, I'd suspect as it's not been smoking it's probably a hybrid/standard with uprated seals...

Well i put the standard CAT back in today and i didn't expect the car to feel quicker.

Not only does the car sound smoother, but the boost holds much better. It's a little less aggressive coming in but when it does it holds all the way through the revs. Car seems more drivable too.

I will probably keep it like this now