I have been told at my last MoT that the exhaust is "heavily corroded", so I was thinking about the possibility of replacing it with a stainless performance system - a small BHP increase, fruity noise and lifetime guarantee being the obvious benefits.

Does anyone have experience of getting a car through an MoT after a sports exhaust has been fitted? Or can you get systems that feature catalytic converters?

My car is a P11 GT.

Cheers
Ali McB

Your best bet is to get a catback system - replaces everything from the cat converter backwards.

That way you still pass the MOT emissions test.

Noisewise - I had a Chrysler Neon with stainless catback system and twin 4" tailpipes that used to set off car alarms when I drove past and it past it's MOT no problem.

You can play safe and get a performance silencer that is tunable - it has an insert in the tailpipe which you can adjust for "nice" and quiet or take out completely for straight through power and very deep noise.

This is what I've got on my P11-144 Sport+. Normally the Sport+ with the CVT/M6 transmission is very sluggish from pullaway until it hits about 3200rpm, but with a performance system it pullsaway much better and accelerates much easier and quicker.

Plus if the guy at the MOT centre says your silencer is too noisy just take the insert out of the boot and pop it back in the silencer (it only has one bolt holding it in there) :)

You can also get performance cat converters that rob less power, but for the price of them I wouldn't buy one unless your existing cat converter is screwed. I fitted one later on my Neon and for the price it cost I only got an extra couple of BHP.

Thanks for the help.

Can I ask what make of system you have? And where you bought it from or got it fitted?

Obviously all will depend on my insurance company being reasonable when I tell them what I'm planning to do!

Cheers

Ali McB

I bought a Savage stainless steal freeflow backbox (2 1/2 inch inlet, single 4 inch outlet. I've fitted it to the existing piping at the moment using a reducer - later I'll fit 2 1/2 inch piping from the cat all teh way through to the stainless backbox.

The system on my Neon I had made up by Powerflow but sadly I cannot recommend them. Mine was done by Powerflow in Enfield London but went back numerious times because it kept knocking underneath and eventually had to be completely rebuilt by them and they still didn't get it right.

This may just be a problem with the Enfield branch (A1 Auto's) but I don't know either way. I used Powerflow in South Africa on my Astra and they were excellent.

Hope this helps.

-=Sean=-

Hi there,

I recently had a Powerflow put on my 1996 p10, consisting of a double bore pipe, 2" by 2.5" oval each pipe. Its Tip Top. It sounds and looks damn good.

I had mine done in Sergeants Motors, Yeovil and so far have had no problems. The beauty with Powerflow is they give the exhaust a free MOT once a year and if they find any problems, they give a full replacement.

Thanks for the information - I guess the Powerflow contains a cat?

Thanks for the information - I guess the Powerflow contains a cat?

No probs...Mine in particular I had built from the cat back so the car has its original cat. They roll there exhausts out using your old one as a guide like a key cutting machine, so I dont see any reason why they cant put a cat on..

They can do a cat replacement when they do the rest of the exhaust but unless your engine is seriously modified I wouldn't bother replacing the cat unless your original one is screwed.