205 Gti Performance Catalytic Convertors

[martyn180 9]

Can they be brought from anywhere?? I have a late cat car, but dont want the hassle of changing the exhaust each MOT, and I assume would free up the missing 8 bhp from the original 130 bhp as I am not away of any other differences? The rest of my exhaust is a proper peugeot item approx 18months

[Luca 1]

I reckon you should weld a v6 model cat in it's place for higher flow

[Anthony 1,003]

I assume would free up the missing 8 bhp from the original 130 bhp as I am not away of any other differences?

No, as there is other differences as well, such as lower compression ratio, milder cam, and tuned for 95RON petrol IIRC.

 

It's worth double checking whether your 205 actually requires a CAT for the MOT, as it's done on the manufactured date of the car rather than the registration date. Just because it's a 92/K reg (for example) thus doesn't mean an automatic CAT test requirement.

[rubyna 4 1 Cars]

Im pretty sure if it was before August 92 that you dont need a Cat, but stand to be corrected? The last 2 205s ive had have had cats, and to be honest

i wouldnt really worry about the little bit of power loss, as very few pre cat 205s rarely made book figure anyway !

I allways found the later motronic car better in mid range power for definate, plus you get the benefits of a steady idle ie no kangarooing lol,

and better fuel consumption.So to sum up if its before the cat is needed get a std pipe and get a lambda boss welded in [few pound on flea bay],

thats what i done with my current car with a magnex four branch and magnex exhaust.Miles on here runs a later cat model 205 and he,s of the same

opinion about the mid range and bhp difference..

[CaptainK 11]

I have one of these on my 205 1.9 GTi (now GTi6) :

1.9 GTi Sports Cat

 

Mine is a 1993 "L" reg and is the 14th to last GTi made according to its VIN number. Thus needs a cat.

Edited May 27, 2009 by CaptainK

[welshpug 1,661]

You don't have to have a cat on the car at all, but it does have to pass an emissions test to be road legal, for which the catalytic converter becomes quite useful if its post August 93 (afaik) if its on a standard management system, though I have heard many get very close.

 

If its on mappable management its perfectly feasible to tune most engines to pass the emissions tests without a cat.

 

However I'm not sure how the MOT interpret the rules for 1992 and earlier cars, built and registered with a cat before the changeover? (9th oct 92 BTW...)

Edited May 27, 2009 by welshpug

[CaptainK 11]

You don't have to have a cat on the car at all, but it does have to pass an emissions test to be road legal, for which the catalytic converter becomes quite useful if its post August 93 (afaik)

Oh yes, if you want to be specific then yes a car only needs to pass an emissions test. Whether its passes it with or without cat is irrelevant. I just have a cat on mine as it needs it to pass the test.

 

However, when my fully mappable DTA management goes onto it later on then my Cat might not be needed. But I'll probably keep it anyways for a bit of backpressure and torque etc.

[martyn180 9]

Capt.ian, did you put the cat on it when it was standard, did it run well?

[CaptainK 11]

Capt.ian, did you put the cat on it when it was standard, did it run well?

Unfortunately not, the Sports CAT was installed shortly after the GTi6 engine was lumped into it. Didn't really notice any difference in performance of the 205 GTi6 with normal 1.9 GTi CAT on compared to 205 GTi6 with a Sports CAT on. There probably was a little bit noticeable only on an RR, but I'll never know. I did intend on doing back to back normal CAT vs Sports CAT RR testing, but alas my sports cat piping was butchered during its failed fitment when the GTi6 engine went in (the sports cat was supposed to be fitted then as well). Which meant later on I had to chop my original CAT piping and weld the sports CAT into it to make it fit.

 

So my advice is that if you need to replace the CAT, then deffo get a sports cat one. But if yours is fine then don't bother as I didn't really notice any real improvement.

 

Still, at least its all stainless now so at least it won't rust.