Welcome to our resource for MG Car Information.



MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGF Technical - TF Exhaust Output

I've had my TF 135 since mid-April and have noticed that the output from the exhaust appears to flow 90% through the passenger side pipe and 10% through the driver side pipe. This is resulting in the passenger side pipe getting quite black, whilst the driver's side is as new. A month or so ago I met up with Alan Dunlop to compare the ride quality of our cars and his exhausts seemed to be pretty much 50/50 as have a couple of other TF's that I've seen about.

Does anyone have any experience of this / idea why it is happening - or is it a "back to the dealer" matter.



Hmmm, i am not sure about this, but i think the TF has a vaiation on the Trophy exhaust system which has (i believe) a valve on the right hand side which opens up or closes the pipe depending on the revs. I thought this was a mod to allow the car to still sound 'sporty' at high revs, but still be quiet enough to pass the drive-by sound regulations.

Anyway, if your TF has a system like this, then this could explain why one pipe is more dirty than the other.


The TF does have a Valve on the Exhaust.
Paul Lathwell

I know a guy in work who bought a new TF . Only 1 exhaust works . The dealer and rover seem unable to fix it.

The valve got named ANC-system here in D in a magazin which did an article about the new Elise 111s.
ANC ... automatic noise control.

Dieter Koennecke

You can see a picture of the exhaust flap/valve on my 135 at

It either permits or denies the flow of exhaust through the RH pipe.
(a good pipe to use during emission tests I reckon :-)

It is vacuum operated; the vacuum is held in a reservoir fed from inlet manifold.

The exhaust flap is sucked open by the operation of an electrical switch which opens a valve in the small plastic vacuum tube between the reservoir and the exhaust flap. shows reservoir and switch mounted in rear right hand wing.

I don't know when it gets triggered (by MEMS) I'm afraid.

I guess they paid for this complex contraption by removing from TFs the under bonnet light, 2nd horn, ign switch light and map pockets in seat backs :-)


ps - dieter please store photos with others on your site if you wish
John Thomas

I think Roger mentioned the other day that the removal of that 'valve' would cause the OBD light coming off. Indeed related to MEMS connection.
2be explored by someone then ;)

Thank you for the great pictures and the permission to use !!

Dieter Koennecke

It would be fun to fit this TF system to a MGF, and use a manual switch to operate the valve - then you have noisey and quiet modes at the touch of a button! :o))
Rob Bell

I recognised the email address you had Tomas. What are you studying at Bath uni? Which year?
I am studying IMML year 2. Do you have a TF or F VVC? What is the wheater in Bath?


Philip Blomquist

This thread was discussed between 12/07/2002 and 15/07/2002

MG MGF Technical index

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