Vibration through exhaust a4

[fitzyr]

I have 2002 a4 1.9tdi 130bhp. I remapped it with an upsolute remap to 160bhp.
Lately a vibration seems to be travelling down exhaust system from the area of the catylitic converter when I accelerate. I have checked all exhaust fittings and they are all fine. Would the Cat need to be replaced because of the remap or what could the problem be. There is 128k on the clock.
Cheers.

[jimmyb]

Amateur Im at 205k!

[fitzyr]

Have you any solution to my problem. Cheers.

[jimmyb]

What happens if you simply rev up to 4-4.5k whilst stationary?

[fitzyr]

I will try and see. Cheers

[fitzyr]

It only seems to happen at 2k. It is fine after and before that.

[oakdale]

This could be many things, but I think your car has a dual mass flywheel and that could well be the culprit with your symptoms.

[fitzyr]

It happens also when car is stationary and I rev up past 2k.
Cheers.

[oakdale]

How do you know the vibration is coming from the exhaust?
Is it a heavy or light vibration or is it more like a noise?
Does it alter if you depress the clutch?

[fitzyr]

When I stand at back of car and get a mate to rev car I can hear the vibration coming down through exhaust. Depressing clutch doesnt make any difference. The vibration is heavy enough and very noticeable at 2k. When driving, the vibration seems to come from the area of cat and travel out under centre console.

[oakdale]

When you hold it at 2000 rpm, can you hear a rattle from the exhaust or just feel a vibration?
If it's just a vibration, then I would suspect the DMF, in the early stages of failure the internal springs and dampers start breaking up and cause the flywheel to go badly out of balance.

[fitzyr]

When I hold it at 2k, there is just a vibration, no rattles 0r anything like that.

[fitzyr]

Dont think it is DMF as it has been like this for a good few months and is not getting worse.

[fitzyr]

Has anyone else got any ideas on my problem. I think it maybe something to do with the cat. I was thinking it could be that it is getting blocked.
Cheers.