Emissions & CAT

[Baz]

Just wondering about something for the future....MOT isn't till October but.


CAT is in Manifold on my car, or at least would be. I have a magnex on my car currently with a de-cat pipe. If i was to put the CAT under the car would it pass MOT?

[steviet]

i take it you mean you have the mark 2 . and have a 4 branch mani on it. and want to put the cat under the car for the mot time? if so yes it will be fine with cat underneath. thats what im doing also

[Baz]

i take it you mean you have the mark 2 . and have a 4 branch mani on it. and want to put the cat under the car for the mot time? if so yes it will be fine with cat underneath. thats what im doing also

Basically yes....just wanna make sure, make it easier for my dad come MOT time :P

[TU-Tuning]

I may be a lying cunt, but surely if your ECU is programmed to sort out the fuelling and monitor emmisions using two lambdas, and you wont have them in the right place as the cat will be too far back, wont your emmisions be funky?

[steviet]

will be fine mate. im doing the same as i had to put the mark 1 mani on ma car as its adapted for the turbo. and im not putting it back standard again for mot time. im just putting the full mark 1 system/cat on to solve ma problem. i don`t see why it wouldn`t work as its just were moving the cat.

[steviet]

I may be a lying cunt, but surely if your ECU is programmed to sort out the fuelling and monitor emmisions using two lambdas, and you wont have them in the right place as the cat will be too far back, wont your emmisions be funky?

the first lambda is in the same place. its the second one on the mark 2 that makes sure there`s clean emissions coming after the cat. but that will be in a sleeve so no engine management light and it will be tricked to thinking its still doing the same job as before

[TU-Tuning]

Fair enough mate, only thing im thinkin of is the mk1 setups only got one sensor before the cat, the mk2s got two one before and one after the cat and the ECUs gonna be reading off of both of these.

When you put the second sensor in a sleeve when you decat it its monitoring the normal air so will have low Co2 readings, in the std mk2 setup it goes after the cat and would alter the fuelling to sort out high emmisions so if theres no reading from the other side of the cat, and the sensor thats meant to be there is reading clean air, there could be emmisions problems if you see what i mean?

[TU-Tuning]

the first lambda is in the same place. its the second one on the mark 2 that makes sure there`s clean emissions coming after the cat. but that will be in a sleeve so no engine management light and it will be tricked to thinking its still doing the same job as before

yeah i getcha mate, just thinking although the car may think its not giving out high emmisions, if theres no lambda where it should be it might be giving out high emmsions without knowing it?

[steviet]

i see what you mean aye ,but would that mean every mark 2 that is decatted is gonna have the same problem.

[TU-Tuning]

yeah but it wouldnt notice unless you got an emmisions test would it, mine runs very very high Co2 readings, 3 times the limit, and I have a std system with no lambda error readings. I only found out on MOT day

[steviet]

very true mate. but im sure in ma mind it will be fine. as the vtr i used to have, used to smoke pretty badly and to ma supprize it passed mot no bother.

[TU-Tuning]

Yeah wish the both of ya good luck, emmisions can be well random on saxos from what ive seen lol

[MaRiO89]

Mine was a cunt MOT time..:(

[TU-Tuning]

Mine too, 4 driveshafts and 3 MOTs ftw!

[Baz]

Anyone know for definate?

[AlexR]

People have had problems getting the car to pass with a cat under the car when it was originally made with a cat in the manifold, but with a healthy engine and under car cat it should be alright.