Help settle an argument about Catalytic converters in Diesels.

[poyta]

Friend of mine was arguing with me the other day that Diesel engined cars don't have catalytic converters nor do they have the need for them. I know that my GT has a Cat built into the DPF filter and the new Mk6's have a separate Cat in the system so It seems that they do come with cats. Any reason why he'd be so convinced ?

[Transporter]

It might be even in the brochure from the dealer that there is CC with DPF.

[gldgti]

Diesel engined cars definately do have catalytic converters. Whether they have need for them is another matter entirely.

I think there must have been some legal area in the 90's where diesel commercial vehicles might not have had cats as mandatory equipment, however that is certainly not the case now.

you only have to climb underneath to see anyway...or look in the uder manual, or even under the bonnet (theres usually a sticker about emission control systems somewhere under the bonnet). Often they say something like "DO NOT OVERFILL OIL PAST MAX LEVEL - DAMAGE TO CATALYST WILL RESULT"

[Gigitt]

My 1996 VW Golf TDi 1.9lt has a Catalytic converter.

[Preen59]

My caddy definitely has a big ugly cat i'd like to get rid of..

[jazd]

Show him that self study pdf on the DPF that was posted in another thread. Goes into detail about the catalyst coating on the inside walls of the DPF.

[Greg Roles]

Diesels still produce oxides of Nitrogen and Sulphur, the whole reason cars have a precious metal cat. As Jazd mentions above, the cat and the particle filter have been separated in the MK6, to drop the expense of changing out the particle filter when it clogs, as the cat component should be good for life ( although you have to wonder just how effective when covered with soot, well the pre DPF cat at least! )

Even if I was going to remove the particle filter entirely, I'd still put an aftermarket Cat back in, just to reduce the pollution overall, and high flow ones hardly affect power really, especially in a low revving diesel.

[Evaded Motorsport]

In England it is legal for them to remove the Cat as long as they still meet emissions testing which has to be performed every year. Most of them still seem to pass emissions testing without too much of a drama.