Cat Converter removal?

**Gubb** · 11th November 2009, 10:41

So, i'm thinking of cutting out the enermous cat converter that currently resides under my bike and welding in a straight through pipe. It more for the loss of weight than a performance issue, but a few questions have arisen.

Is it legal? Will I be able to get a WOF without it?

I assume a tune would be necessary?

**pritch** · 11th November 2009, 11:21

Minimal information but...

Ducati offer sets; pipe cans, and filter, that do away with the cat. These sets include a new ECU. They could also pose a noise problem at WoF time?

If the bike has carbs you might need to rejet, if it has efi you might need a Power Commander.

Depends whether your cans are standard or aftermarket too.

There can be other problems, some BMWs start to backfire something chronic when the cat is removed.

**The Stranger:Me** · 11th November 2009, 11:47

Originally Posted by Gubb

So, i'm thinking of cutting out the enermous cat converter that currently resides under my bike and welding in a straight through pipe. It more for the loss of weight than a performance issue, but a few questions have arisen.

Is it legal? Will I be able to get a WOF without it?

I assume a tune would be necessary?

Both my cats are gone and I have no problem with WOF.
My bike didn't need a retune for that, and it improves midrange performance.
That said, that was well tested by Ivan first and yours is likely to be different, though I doubt it will need re tuning

**vifferman** · 11th November 2009, 12:19

In theory, the bike can be failed for having the cat removed (if it's OEM fitment, it's supposed to be there). However (but!) it depends on (a) the tester being aware it's been removed, and (b) giving a rat's about its removal.

There's a few guys I know who have cut open the cat on the VFR and removed the innards - you can't actually tell it's been done. Seems a bit pointless to me,as it doesn't liberate noticeable ponies (only those little Shetland bastids). I'd much rather remove the whole thing as it's large, ugly, and it's mounted right under the bottom shock mount, so I'd imagine the heat from it doesn't do the shock any favours. Trouble is, it's connected to the two rear headers, so it would be a job for a talented welder to make a replacement.