Hi,

My 98 turbo 2000 failed its MOt yesterday with emmisions

Fast Idle Test
CO 0.24%
HC 2686 ppm
Lambda 0.94

Second Fast Idle Test
CO 0.15%
HC 1384 ppm
Lambda 1.29

The Car is Fitted with a Sport Cat and decat Centre, the tester said it sounds like its misfiring?

so anyway, i take it home and pull out the plugs to check and the one on the drivers side at the front is running very rich, the other three are clean.

Any idea's what might be up, do the MY98's coil packs cause this or is it a Lambda sensor?

Cheers

 

I had exactly the same problem (failed MOT on emissions) on a MY00 Turbo 2000 and it turned out to be my Lambda sensor. I've got a sports cat and decat centre section aswell, and the garage were convinced that this was the problem. I told em it should pass like that and it'd passed the year before like that aswell. So I re-fitted the entire standard subaru exhaust from the turbo back.....and it still failed lol. So yeah, turned out to be my lambda sensor. I had no issues with my spark plugs tho so I'm not sure about that affecting it on yours?

 

I would have thought the Lanbda would have done all the plugs though this is whats confusing.

 

Its possible your coil pack has failed, although normally the failure is on a pair of cylinders on the 98 with wasted spark.

HT lead, plug failure/fouled?

Simon

 

Thats not a lamda problem. The hc's are way to high meaning too much fuel. Missfire is most prob the cause

 

Just been to a garage near wher i work that seem to know what there talking about, the mechanic syphoned out some water and then ran put a tester on that turns green if there are HC's in the coolant, guess what it started going green. he thinks that the head gasket or head is failing causing the misfire and the resultant high HC's in the emmisions.

Does this sound alright, the car did blow its top radiator hose about 6 months ago, but as it had been alright before and aftre i did not think much of it.

Any ideas's appreciated

Cheers