964 - Will a 100 cell pass the mot

[hot66]

Looks like my 964 isn't going to pass emissions with the cat bypass I have fitted .. I swapped in the bypass earlier this year ( sounds great ) as my original cat had split at one of the welds.

We sort of did a pre MOT today and it failed emissions as it stands. ( from memory we couldn't get it below 0.3% Co required and I think we were at 0.515) . It's a 93 model, registered as Dec 92 so technically I should run a Cat .

So, can anyone confirm a 100 cell cat ( specifically a danske ) on a 964 will pass the MOT ? Dont fancy spending £700 + just to find out it still fails.

Worst case I can keep refitting the stock back on for MOT time but thats a bit of a ball ache.

Seems to be a distinct lack of 200cell cats available for the 964 from the UK suppliers nearly everyone has 100cell only. TBF I like the noise of the decat, so a 100 should be fine too it s just trying to find a straight answer about the MOT. The internet is surprisingly void of any feedback

Edited by hot66 on Thursday 9th October 08:54

[ChrisW.]

Does it need a cat ?

My 964RS consistently passed the non cat MOT because the car was homologated prior to the cat being a requirement ??

[Grey_Area]

Possibly, mine was touch and go especially as it wasn't in the first flush of youth.
99ron, and an Italian tune up, freshly serviced with a decent air filter and mine was marginal...

[guards red]

My 993 did a number of times. However it only passed at fast idle on the second pass.

However, given 100 cell cats are touch and go anyway, I would aim at high quality cats -lesser ones may pass the first year but decline rapidly.

All the above is based on limited experience, I'm no expert!

[996Type]

I did a full decat on my 95 993 and it would pass but only when at decent temperature, which was a pain.

I got the tester to do the test first upon delivery and it was OK, but the back of the car (wings) seemed to be red hot even with temp shields etc in place.

Did look / sound great though when I competed the work!

[hot66]

Thanks for the replies.

Unfortunately due to date of first registration on the v5 I can’t get away with the earlier test and with all the mot testing getting digitally linked it can’t really be fudged

Having spoken to others it does seem a 100 cell isn’t going to do it so I think I’ll try and find a 200 cell ( only seem to be available in Europe ) and see how it goes.

For now I’ve swapped in the original cat, which we’ve welded up where it had cracked, and going to get the mot on the car again