Cat bypass pipe and MOTs

Post Reply
David
Posts: 9
Joined: Tue Aug 17, 2021 5:28 pm
Contact:

Cat bypass pipe and MOTs

Post by David » Fri Mar 25, 2022 10:07 pm

My Nomad needs an MOT and I have a cat bypass pipe fitted which is how it came when I purchased the car back in September. The dealer has been a little slow sending me the catalyst (previous owner took a while to find it apparently) and I should have it next week.

I understand that the car will not pass an MOT without it fitted and I wondered how easy it would be to do the swap myself?

I've searched this forum but couldn't find any mention of anyone doing it on Nomads but there's lots of talk in the Atom forum where they make use of a club cat. Given how many people have used it I'm guessing it's pretty straightforward? The only pictures on that thread have expired and can't be seen hence my raising the question.

Let me know how easy (or hard!) it is if you've done it.

Thanks!
David

User avatar
stupot
Posts: 369
Joined: Fri Aug 19, 2005 7:44 pm
Location: Gloucestershire
Contact:

Re: Cat bypass pipe and MOTs

Post by stupot » Fri Mar 25, 2022 10:23 pm

Hi David,

It’s really easy. Remove the 6 nut and bolts holding the bypass pipe and replace with the cat. I find it helps to loosen the top nuts from the mounting bobbins that mount the silencer to give it bit of vertical play.

Stu
Atom 2 160 (05-11) / Atom 3 245 (12-19 ) / Nomad 300 (22-)

David
Posts: 9
Joined: Tue Aug 17, 2021 5:28 pm
Contact:

Re: Cat bypass pipe and MOTs

Post by David » Sun Mar 27, 2022 9:49 pm

Am pleased to report that it was as straightforward as you described, Stu. Thanks for your help!
Attachments
136296E4-502D-44A2-B5A9-9F2A58DB8828.jpeg
136296E4-502D-44A2-B5A9-9F2A58DB8828.jpeg (2.87 MiB) Viewed 2178 times

BlueIn2Red
Posts: 19
Joined: Tue Sep 27, 2022 1:52 pm
Contact:

Re: Cat bypass pipe and MOTs

Post by BlueIn2Red » Mon Oct 03, 2022 2:47 pm

Is it confirmed it won’t pass the MOT without the cat? My just acquired car appears to have passed three MOTs without one…

User avatar
John Scherrer
Global Moderator
Posts: 5124
Joined: Sat Mar 07, 2009 1:20 pm
Location: Willington, Bedford UK
Contact:

Re: Cat bypass pipe and MOTs

Post by John Scherrer » Mon Oct 03, 2022 3:14 pm

It won't pass a legit MOT test !

Are you sure the previous owner didn't take it to Ariel for service and MOT?

They fit a CAT before taking it for its MOT test.
Atom 3 310 Supercharged (2011), Now Sold

BlueIn2Red
Posts: 19
Joined: Tue Sep 27, 2022 1:52 pm
Contact:

Re: Cat bypass pipe and MOTs

Post by BlueIn2Red » Mon Oct 03, 2022 5:27 pm

Interesting, thanks. Mine wasn’t done through Ariel no. Do you happen to know if it fails because of the pure emissions numbers, or simply because the cat is absent when it should have one?

atomiser
Posts: 264
Joined: Tue Nov 01, 2005 7:08 pm
Contact:

Re: Cat bypass pipe and MOTs

Post by atomiser » Sat Oct 08, 2022 9:39 pm

Definitely fails on emissions. CO and probably HC. Both idle and fast idle - or at least on mine (K20Z4 s/s)

Depending on what the cat looks like I.e. looks like a cat bypass then it will probably fail on visual inspection as well

BlueIn2Red
Posts: 19
Joined: Tue Sep 27, 2022 1:52 pm
Contact:

Re: Cat bypass pipe and MOTs

Post by BlueIn2Red » Sun Oct 09, 2022 1:08 pm

Just a warning for Nomad/2.4L owners - the gaskets used for the cat section aren't metal as (I believe) on the 2.0L, so there is less chance of being able to re-use them as they might well fall apart on (dis)assembly ... mine certainly did, so with my MOT due on Wednesday I hope the factory are as efficient as usual in getting new ones out to me!

GavM
Posts: 8
Joined: Tue Apr 21, 2020 8:29 pm
Contact:

Re: Cat bypass pipe and MOTs

Post by GavM » Tue Oct 25, 2022 8:13 pm

Just gone through this process and Cat replacement was easy. Remember to check headlight alignment, i got lucky. Also hydraulic only handbrake won't suffice. Good luck

Post Reply

Who is online

Users browsing this forum: No registered users and 4 guests