Car just failed it's MOT emission test even though I spent last weekend putting all the original exhaust back on! It's a MY98 Type R.

RESULT:- Lambda 0.95 (too low) and CO2 1.84 (massively too high!)

The MOT guy said it could be the lambda sensor? The things is though, I'm still using a Power FC that was mapped for a full decat exhaust. Could this be the problem, as the lambda reading is only just outside the pass range? If I stick the stock ECU in do you think it will pass?

Thanks.

 

Highly unlikely...You will need a new lambda sensor by the sound of it...You could check the voltage on the signal wire to see if it is cycling or trying to pull the mixture down , if this is so it should show a high voltage all the time....

 

Just to answer my own question (and thank MartynJ for his reply)...

I fitted a generic lambda from Universal 3-wire Zirconia Heated Oxygen Sensor :: Gendan Automotive Products

Car has now passed it's MOT with a result of lambda 1.00 and CO2 0.06 (i.e. about 30 times lower!). Strange thing was I felt no difference from replacing the lambda - there were no symptoms that the lambda had failed.

 

Is the O2 sensor switched off in the commander settings?

 

Good question! - I basically changed the lambda and put the original ECU back in. It passed the MOT re test yesterday but I'm not sure if it was the lambda or ECU that caused it to fail origially.

Where about's in the settings is the O2 sensor bit?

 

Well, I've just plugged the PFC back in and have discovered that the o2 sensor was switched off! No wonder the thing failed the MOT. Looks like I've wasted my money on a new lambda as well!

I wouldn't have minded but the first thing I did after it failed the emissions test was go to the place that mapped it asking if they had any suggestions and if they could confirm if the lambda was working or not. Bloke said "we'd have to plug the diagnostics in and check if the lambda was switching" blah blah blah, etc. Seems if he'd have known what he was talking about he could have just had a look at the commander and changed one setting, saving me a lot of time and money! Think I'll be taking my business elsewhere in future.

For anyone else who (like me) didn't know about this setting, it's the 5th one down under etc. / Function Select... "O2 F/B Control"

 

Borrowing this thread!
I have the same problem with my TypeR 99. Way to high CO and a to low level on the lambda.
My problem is whether or not I should buy a new lambda or maybe the O2 sensor. The CO is up between 6.3 to 9 between idel and 2500 revs. The lambda reading is 0.80 if this tells you anything?
My handcommander seems to be locked. It says "Apexi" on the screen and all that happens when I turn the ignition on is that it illuminates...
Another problem is that one of the connectors to the O2 sensor seems to be unplugged! It seems as if it has no connector to fit to. And of course I have the O2 sensor plugged in accordingly...
My Apexi turbo timer says the O2 value is between 0.02 and it increases to about 7 just after it starts up. But this is no correct value I m told. Please help me.
What to do?
Change the lambda?
Change the O2 sensor?
Remap the Apexi?
Buy a new exhaust with more then one cat?
Cheers lads