failed MOT with precat delete

[jedi-knight83]

Well... I say failed... Technically it failed but its all about WHO you know 

Anyway... I thought the pre cat delete didnt affect emissions?

I dont have the actual figure but I was told the lambda reading wasn't within tolerance for the MOT?

Anyone else had this issue?

[ashw831]

Had my mot done  last week, and with my pre cat out I had the same issue as you, but as you say it is who you know!! ;-)

[sub39h]

I thought the pre-cat only affected cold emissions, and that it was only necessary in Germany?

My BlueFlame (obviously without pre-cat) passed it's MOT at an Audi main dealer only last month

[GrayMK5GTI]

Mine sailed through the MOT with the pre-cat removed  (at a VW dealer).

I did take it for a thrash down the bypass before the MOT to get it hot. The pre-cat aids cold start emissions so if the car is hot when it's MOT'd it should be fine.

Sounds like your normal CAT may be at fault 

Gray

[jedi-knight83]

Mine sailed through the MOT with the pre-cat removed  (at a VW dealer).

I did take it for a thrash down the bypass before the MOT to get it hot. The pre-cat aids cold start emissions so if the car is hot when it's MOT'd it should be fine.

Sounds like your normal CAT may be at fault 

Gray

Sounds like a good excuse to upgrade my downpipe and cat then :)

IS there anyway to check the main cat?

[jedi-knight83]

If it makes a difference... i'd not used the car for about 6 days prior to the MOT and it was a very short drive through town to the garage. I dont know how hot they then got it?

[micky 32]

I have no precat and running a high flow Miltek cat and emissions were well in spec. Must be yoyr normal cat faulty.

[bacillus]

Sounds like they did the MOT without preheating the cat...

[jedi-knight83]

i might take it for a blast and then pop it in next week for them to recheck emissions when its hot.

If it still fails I will look at getting a miltek downpipe and sports cat.

[PDT]

If it failed on lambda readings then it's not the precat at fault, it's either running too rich or lean. If it filed on hydrocarbons or CO then it could be blamed on the precast removal.

[jedi-knight83]

If it failed on lambda readings then it's not the precat at fault, it's either running too rich or lean. If it filed on hydrocarbons or CO then it could be blamed on the precast removal.

Hmm.. I'll message R-Tech then. Annoying if it needs adjusting as its running beautifully at the moment.

[donovan2123]

I have passed 2 mot's with precat removed at two different garages one being kick fit and it passed with no issues.

[Ree]

Hi,

Sorry to High-Jack

What the performance advantages of removing the pre-cat, also does anyone know if this can be removed from the R32 !

Cheers Peeps.

[56OctyVRS]

I always take my car for a long drive before the MOT to heat up the cat and the brakes etc to make sure it passes easily. My car passed with the precat delete this year and passed with ease.

[jedi-knight83]

as PDT said above.... seems my issue may not be cat related at all but fuelling related.