Do Diesel cars need a cat for MOT?
 

Other halfs Golf GT TDI downpipe with cat has just split in two. Milltek do a s/s downpipe without the cat. Reading the MK IV forum it looks to me that Diesels don't require a cat for MOT's - anyone confirm this?

p.s. don't believe what they say abour reliable VW's:rolleyes: - after 5 years with both cars, my STi v3 is way better....

Can't confirm m8, but my PUG 406 TDLX (only owned her for 3 mths was looking thru receipts) had a new cat fitted to her last year, judging by the date it was done for the MOT as there was only 3 days difference :)

No mate, diesels dont require a cat for a MoT test, just the emissions need to be below a standard.

Nick

Do they need a dog??

LOL @ SwiftNick.. surely they might need the cat to pass the emissions!

Emission tests for diesel are based on the opacity (how clear) the fumes are from the exhaust. i.e the carbon content.

The cat doesn't really do that much to affect this (they are there to get rid of the carceogenic gasses rather than the carbon).

So, with it warm and idling, boot it and hold it for just under a second, (or before the rev limit). If there is very little or no black smoke it will probably pass. Diesel emission tests are based on a fairly crude system (much like a smoke detector for your house - just using a light bulb instead of some radioactive stuff). I've seen overfueling diesels (lots of white smoke) pass to my amazement.

Cheers guys, thought this was the case. Replacement downpipe with cat from Eurocarparts is £287, stainless steel downpipe from Milltek is £145 - now which one will I choose;)