I've just spent a fortune on a forged rebuild on my V3, plus simtek. I also put on a H&S sport cat downpipe to save the hassle of swapping at MOT time but it still failed on emissions and they had to put a second cat on? My car had a new O2 sensor put on and apparently mapped beautifully (and by a very well respected mapper). Is it because the simtek runs slightly rich for safety?????

 

If it has switchable maps, get an MOT map for it !

dunx

 

i fitted a sports cat
and mine failed mot went back to manufacture and they said
cat had to get well hot before test once its hot all is OK

 

I was wondering about this. Can you map it to pass an MOT with no cats at all?

 

Ok thanks for the advice. I wish i hadn't bothered with the sports cat now!

 

did it fail on LAMBDA or co and hc?

if lambda passed then the fuelling is fine so it is not the map or the o2 sensor but the cat not hot enough or working well enough.

Simon

 

I had a similar issue on mine recently. Have the Ninja sports cat and up til this year it had always got me through the MOT. This time around it passed cold idle but failed on the fast idle test.

The difference between this year and other years......the weather was a lot colder this year and apparently sports cats only work effectively when hot. Therefore if your car is left in the cold for a while before testing the cat may not be functioning as it should be.

Ns04

 

IMHO it is do-able, but not in any safe for road use.

dunx

P.S. Perhaps JGM will comment on my optimism.....

 

if you upped the power to the starter motor so you could spin it over at 2500rpm with ecu off.. easy.. no emissions

 

I once bluffed a car through MOT on a PFC, just on the Cat test, car was on a full decat.

Not sure who told me how to do it

 

It doesn't effect me much anyway as my car has the emissions of a 1.2 Corsa apparently. Was just wondering if you could have an "MOT" map and then switch back after. I will be getting a sports CAT eventually just to make sure.