Removal of pre-cat

[johnvx220]

When I ran a couple of vx,s and I had the pre-cat taken out of both (this was where the manifold meets the exhast and only put there to comply with eec rules). On the turbo model the space where the pre-cat was replaced by a straight pipe. This did not effect the the ecu. This increased bhp to the wheels, was more free reving and more mpg. I havent heard of anyone taken theres out or if it is even possible. Just a thought for petrol lovers.

 

[DanGB]

Is the pre-cat the same as the Cat?

If you remove the cat i beleive it will throw up all sorts of errors. And of course will probably fail the MOT and be illegal. better of just getting a 200cel sports cat.

 

[Pummy]

Sounds about right as the restrictor is removed.

This sounds like there are 2 cats from the turbo back? Could this be the flexipipe or downpipe you are referring to by 'pre cat'?

Just a few points of concern though...

1) VOSA Inspectors might be able to detect the removal of the pre cat by the change in exhaust gas composition?

2) MOT time failures due to same exhaust gas measures changing?

 

[johnvx220]

The pre cat only does the job of the normal cat, but when the engine is cold as the normal cat doent work until its up at working temp. That was the beauty of the replacemnt pipe, the org could always put back in.

 

[m0rk]

is there one on the 2.0TFSi?

 

[Pummy]

I would have thought that when the CAT is not up to temp, would the ECU not simply adjust until the it is up to temp?