Anybody know the requirements for a cat on a turbo diesel?
My son is looking to put a stainless system on his V reg 306 HDi, there are 2 options one that will replace the cat and one from the cat back.
Is a cat a necessity on a diesel? will it fail the MOT on emissions without one
My renault master used to pass MOT's without the cat.
Is a cat a necessity on a diesel? will it fail the MOT on emissions without one
I "think" that if it had one fitted from new, then it needs to be working for the MOT.
Having said that, my brother's Xantia passed it's MOT last week after having replaced the original cat/exhaust with a new cat-free one.
After a google-group search it seems that MOT testers have no idea which cars were fitted with a cat, so if your car passes the emmisions test, they
don't care 
Just keep the old system, if it fails its MOT without it just whack the old one back on, not much of a hassle if its just from the downpipe back.
Bit of a pain if it does fail, but at least you will know for next time.
Also i have heard of petrol cars passing with de cat systems, just happen to be under the limit somehow.
quote:
Originally posted by greggors84
Also i have heard of petrol cars passing with de cat systems, just happen to be under the limit somehow.
