without sounding to ask a silly question, can you fit a Mk2 petrol vRS back box on a diesel fabia!?

I realise the bore sizes will probably differ but apart from that would it change anything else?

Cheers.

Where's the DPF in the diesel and the cat in the petrol?

Also, the Monte hasn't got a protruding exhaust, so you'd need to do some diffusor surgery.

thanks, I didnt think about the cat and dpf but would that matter if it was just the back box be replaced? and rear diffuser surgery would be too much problem.

Diffuser Surgery *wouldn't be a problem* it should read.

Also, the Monte hasn't got a protruding exhaust, so you'd need to do some diffusor surgery.

or £150 for a replacement rear difusser, I've looked into replacing the rear on my Monte but couldn't swallow the price of the diffuser

or £150 for a replacement rear difusser, I've looked into replacing the rear on my Monte but couldn't swallow the price of the diffuser

vRS and Monte diffusers are very different apart from the exhaust cut out, the monte one goes straight across to meet with the wheel arch trims, the vRS angles down either side.

Charles, on the face of it, it may seem like a good idea. But any physical differences aside, there is a strong likelyhood that it will alter the Monte's back pressure enough for you to lose power and or mpg's. The ecu will detect the car running either a bit rich or more likely a weaker mixture and will try to compensate but probable won't be able to. The net effect could be to damage the cat and dpf and maybe your engine if you push it a lot. I know others that have tried this type of thing on other cars and it's sort of worked for 6 months then a big bill has arrived. I've recently been involved in a new diesel engine development project and injection/induction and exhaust gas removal is one my main area's of expertise. Surprising just how a small change can make a massive difference. I haven't any experience of working on a Monte with that sort of change made but I would say to be very careful what you do. The exhaust is tuned to perform perfectly on your Monte in standard form. It pulses just the right amount of back pressure to the manifold to make everything happen correctly. I won't go into technical terms but altering it might not be good. Changing it could cost more than you think. Often cheaper to put the right one on unless you can learn from someone who has done it and can report for sure the car is performing absolutely correctly. But rarely are changes made by owners in this area to a standard engine that bring any benefit. It's usually the other way around. FYI a new CAT/DPF is around £1600 so don't upset it. Damage may not show for several months.