The MGF Register Forums

Good evening,
just had the belts replaced on my VVC and a new cat and exhaust back box as well. Now the car is popping under deceleration, two or three times when cold and not so much when warmed up.
Have changed the plugs, air filter all to no avail !
The only thing that is worrying me is the mechanic who changed the timing belts commented that the timing was out by a notch. Would this cause the car to over fuel if the timing has been set up wrongly ?
Any help or comments much appreciated.

Hi Dunkle,

Sorry, this post do not help you much, but my 99 1.8 MPi have done the same since I bought it 8 years ago.
I do not worry since it does not seem to do any harm. I actually like the pops. It's like a signature for my MGF.

So far I have changed about every service item, like oil, filters, spark plugs, plug leads, rotor, rotor cap etc.
I have also changed the standard backbox to a stainless aftermarket one. Even the cat have been replaced with a new OEM cat.
But the popping is still there.

When I changed the belt the timing was in fact one notch out from the previous mechanic.
I aliged it correctly when I fitted the new belt. That did not remove the pops either.

Thanks for that it appears after a lot of investigation the exhaust is not oem and prone to popping. Just going to live with it.

Popping usually means unburnt fuel. Are you sure it doesn't have a leak somewhere, causing the O2 sensor to read too high? Maybe lots of them have a small leak near the O2 sensor?

Hi,
definitely not leaking and the more I listen to it the more I'm convinced it's the baffles that are gone. That the trouble with buying off auction sites secondhand !

You said a NEW EXHAUST AND CAT.......

Sorry new cat and used exhaust from EBay. Thanks for pointing that out.