Finally happy with my exhaust : MoT update

[pilch]

After not getting on with the backbox I did have on I decided to try something different.

I had both secondary cats removed and an X-pipe welded in their place, followed by the standard backbox. It's a little bit different than bog standard, a really nice sound and the cats gone are certainly going to help with the flow of exhaust gasses.

I then added some some extra exhaust heatshield so it is impossible to say what's underneath meaning it should be good for MoT time

 

[Zedebee]

MOT measures your NOx and CO emissions, which your cats are there to deal with. Good luck.

 

[pilch]

If it's an issue I can just replace the section with the cats for retest..

 

[patriot66]

If it's an issue I can just replace the section with the cats for retest..

You'll be fine. The secondary cats on an almost 20 year old Z4 are doing absolutely nothing except massively hindering gas-flow.
My Z4 has passed 2 MOT's without issue since having mine removed, and the second time with a supercharger fitted also !

 

[pilch]

If it's an issue I can just replace the section with the cats for retest..

You'll be fine. The secondary cats on an almost 20 year old Z4 are doing absolutely nothing except massively hindering gas-flow. IMG-20211218-WA0000.jpg20211218_133506.jpg
My Z4 has passed 2 MOT's without issue since having mine removed, and the second time with a supercharger fitted also !

Thanks mate...last year on MoT time the emissions were so low I'm hoping there's some buffer even with the cats removed.

Jealous of your supercharger

 

[patriot66]

If it's an issue I can just replace the section with the cats for retest..

You'll be fine. The secondary cats on an almost 20 year old Z4 are doing absolutely nothing except massively hindering gas-flow. IMG-20211218-WA0000.jpg20211218_133506.jpg
My Z4 has passed 2 MOT's without issue since having mine removed, and the second time with a supercharger fitted also !

Thanks mate...last year on MoT time the emissions were so low I'm hoping there's some buffer even with the cats removed.

Jealous of your supercharger

Just take your car for a vigorous 10 minute blast to get everything nicely warmed up before you rock-up for the MOT and I'm sure it will be fine
Yeah, I love my s/c

 

[1536Z4]

If it's an issue I can just replace the section with the cats for retest..

Why don`t you just fit some 200 cel high flow cats and save yourself the aggro of the MOT and do your litle bit for the health of everyone else

 

[pilch]

MoT this morning. Breezed through the emissions and no issues with the decat, not that it's visible anyway. No advisories to top it off.

Validates the point above that an 18 year old cat is doing very little/sod all to reduce emissions 8)

 

[1536Z4]

Breezed through the emissions and no issues with the decat

Didn`t read your post properly first time and now see that you are talking about secondary cats ( dont have them on mine ) Good to see it passed so easily Have you noticed any difference in performance / fuel consumption ?

 

[TOMGREEN413]

I'd love to hear what it sounds like.

 

[pilch]

Breezed through the emissions and no issues with the decat

Didn`t read your post properly first time and now see that you are talking about secondary cats ( dont have them on mine ) Good to see it passed so easily Have you noticed any difference in performance / fuel consumption ?

It might just be the bum dyno but it feels a bit more lively and revs so freely.

Fuel consumption? Never consider it on a 2nd car :lol: I might reset the mpg though and see what it says

 

[patriot66]

MoT this morning. Breezed through the emissions and no issues with the decat, not that it's visible anyway. No advisories to top it off.

Validates the point above that an 18 year old cat is doing very little/sod all to reduce emissions 8)