Sorry help needed again exhaust o2 sencor MOT

Ok so i got a mk1 golf gti 1993 with a catalytic converter and accordingly an oxygen censor that plugs into my ECU and also have a 4into1 manifold and a jetex exhaust system made up of a back box silencer straight pipe and a wiggly pipe that should fit onto my down pipe or my manifold if i had it on.
If that makes sence. I need to keep my o2 cencor of it will screw my ecu………………
So what do i do about it? Do i get my manifold and drill an oxygen censor hole? I just dont know
 I just don't know can anyone offer any advice on it? DO i need a cat ect ect has anyone done it??

HELP!!!

 :dontknow:

Help and advice always welcome
Regards Chris

have moved here as you might get a better response

Ok i doubt it as people check 'mk1 chat' as a mass more than exhaust bla ba bla but Thanks anyhow.  

Can't remember the year off the top of my head, but its possible that if your car has a cat, its because it needs a cat (due to its age). Therefore, you canot simply replace this with a 4 branch manifold and sports exhaust system, you'd need to buy a manifold compatible with a sports cat, get one of those, and an exhaust system that can bolt onto this….

If however you don't need a cat, then you still need to retain the O2 sensor. In this case, you'll need to have a bung welded into your manifold (its a standard size and easily obtainable); unless you can find a manifold with one in already.

Ahhh i thought this may be the case ok well i phoned my MOT place and not having a CAT isn't a failure just if i fail on o2 emissions which i probably will if i take it out ie thats why it's there. So what i actually need to buy is a manifold that is compatable with a sports CAT (any know where i can buy that?) the CAT i have on my car is a small CAT and a silencer built in.
Can I also buy a sports CAT?? or will the one i have be OK? or will it restrict??

 

Cheers Paul.c much appriciated

Ok if i have an o2 censor do i NEED a cat? will it effect it, it anyway?
What my plan is, is just to forget the CAt for the time being when my MOT come arounf just buy one and weld it in but do i NEED one now?

ChrisRivage said

Ok if i have an o2 censor do i NEED a cat? will it effect it, it anyway?
What my plan is, is just to forget the CAt for the time being when my MOT come arounf just buy one and weld it in but do i NEED one now?

I think you do, but the MoT regulations don't specifically say that a cat is a required item to be fitted. Basically, all they check for at MoT time is emissions, not the presence/absence of the cat. However since your car was fitted with one originally, the emissions levels required to pass are much tighter than for cars fitted without (and yes, they do check which cars were/weren't fitted with them) and for cat-equipped-originally vehicles, also include a lambda (mixture) check.

Unless you desparately lean out the engine, you'll have no chance passing the CO requirement. And they also check the lambda, which needs to be within certain limits, so they'll know that you've leaned it out to try get under the CO limit and fail it for being out of spec on lambda!

Maybe Bert or another MoT tester can clarify the situation though?

Ok well my plan was to lenghthen the wire and mount the c02 censor at the bottom of my 4 branch manifold (to get an accurate reading) get rid of the CAT and just put in a straight pipe my MOT is 8months away so i will just leave it till then if it fails then i will just chop out a 30cm section and weld in a sports CAT so it will pass the MOT, if it passes befor Bonus! if not, not a major deal only cost ?100 for a sports CAT. (but can't afford that at moment)
Like you said Paul not essential for me to have a CAT but i gotta pass my 02 censor test.
Ok this Lambda mixture test what exactly is that and how would removing the CAT affect that??

The date of registration determins whether the car needs a CAT for an MOT.
When was yours registered?

juz said

The date of registration determins whether the car needs a CAT for an MOT.
When was yours registered?

In theory you don't need a cat for the MoT, just need to pass the emissions tests. But in practice, you can't pass them and have the car running normally, without the cat! I think the date is 31 Aug 1992.

or get the car screwed down on the metering head to pass the
emission's, always had to do that with my mate's that was
tuned

Your correct with your dates paul mine is later its a 93 unfortunatly made in 92 registered in 93 the CAT can be removed but i need to pass the co2 test so..... i just want to know if i remove the CAT and have the co2 will my car and ECU still preform as normal??