I have just got back from having an MOT and it FAILED, A couple of little things, but then there are the emissions..... Its a 95 WRX Import, which is usually fully decatted, i put just the centre cat back in hoping that this would be ok (it has been in previous years) But it failed this time and there are some very strange figures, has anyone got any ideas???? I am not sure that just putting the front cat back in is going to sort it.

The figures that the car had were as follows;

CO Level 10.67%vol
HC Level 216ppm
CO2 Level 8.10%vol
O2 Level 0.37% vol
LAMBDA 0.73

I hope that someone can shine some light on this and hopefully give me a few ideas.

Thanks
Luke

 

Ive got the same problem mate. Everyone here says it is the lambda that is broken. Change it and it should pass.
I have heard everything from the injectors to the O2 sensor to the motor oil and so on. I have decided to purchase a new lambda, Subaru one... Expensive but what the he**...

 

I wasn't sure if it would be the lambda or not, its is possible i suppose. I have changed the oil and filter today and run some injector cleaner into the fuel. And also fitted the front cat back in. I am going to try and get a lambda also. The annoying thing is that there is no way of testing it until it goes back for the MOT retest.

Also what is the sensor in the downpipe, not the main lambda that is in the manifold. Its a bugger to get out. Need to remove it to put it in the cat downpipe.

thanks

 

I reckon you could get an emission test at your local car work shop. It would cost about £10. But as I said. I am only saying what everyone has said to me and we have similar readings and has gone from fully decat 3" to half original except from downpipe cat. So try it. I will on monday buy a new lambda for approx £170. It should be fun and I will probably laugh all the way from the Subaru dealer...

 

Are there two lambda's on there, as i have one in the manifold and then there is another sensor in the downpipe, which i have read is also an oxygen sensor?????

 

I only have one lambda as far as I know, and that is on the downpipe after the turbo charger. As far as the oxygen sensor I beleive there is only the one near the filter end induction and that is the O2 sensor/ MAF. Correct me if I am wrong.