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MG MGF Technical - cat bypass

good evening all just fitted all sorts of alloy bits to the F, got them from MS excellent site well done, a friend of mine has just bought a second hand mgf mk2
after riding in mine, he took it home and under the advise of someone he was told that if he installed a cat bypass it would be louder now i know it can be done to the mk1 but there must be something diff on the mk2 i told him to wait while i check the BBS for advise
Many Thanks
Luis Pereira

Yep, there is a sensor after the CAT on the MK2 preventing the addition of a CAT pipe the MEMS won't allow it, from there on it get a bit more technical.

Rolling Road figures show that there is little gain in power from CAT removal just a bit LOUDER, might be a bit tiring on a long journey :0(

Mikes Exhaust and a K&N is quite loud enough for me, the Miltek takes the biscuit though....

tim woolcott

thanks for the advise Tim i also have a K&N fitted with reg exhaust its fine
Luis Pereira


I would have to disagree with you about the Milltek - just had it fitted and it sounds fantastic.
Blue Pocket Rocket

Bypassing the cat will give you maybe 2BHP extra and the Exhaust is louder but much harsher and not as sweet (depending on make).

It improves MPG very slightly so some will try to tell you that it produces less CO2 and so it's better for the environment. It will produce less CO2 but you will get more hydrocarbons, it may help save the planet but unfortunately it poisons the people.


'I would have to disagree with you about the Milltek - just had it fitted and it sounds fantastic.'

I agree, it sounds great but in a louder, sharper sort of way... :0)
tim woolcott

This is the main reason why I havent upgraded/replaced my mk1 F. I have had this car for approaching 7 yrs the longest I have ever had any car by a factor of 3!
The Mark2 car has that second sensor after the cat which means you cant get radical with replacing the cat which means that it will never sound like mine....therefore I dont want it mate!

go and get a loud K&N filter, it's not musical like the exhauist but at least you'll feel like you have a sports car

hi all
thanks for your input i have just ordered a K&N for my mate unfortunatly there aren't many modded MGF's in BDA and no one has a aftermarket exhaust. I am currently in the market for an exhaust and i have settled for the MS daytona because of looks and from what i read on the BBS MS puts out some high quality stuff but there is really no place to compare miltek daytona remus etc so if i don't like it i guess i'm stuck with it or sell it but that shouldn't be the case
I'm off to UK in January hoping to meet some fellow F enthusiasts in or around London any takes?
Luis Pereira

This thread was discussed between 16/11/2002 and 18/11/2002

MG MGF Technical index

This thread is from the archive. The Live MG MGF Technical BBS is active now.