I had my STI V5 Type R at the Swedish "MOT" the other day and it didn't pass because of the emissions.

Lambda is 0.84 so it's clearly running rich. CO is something like 2.0-3.5 depending on if the engine is at idle or 2500 rpm. HC is somewhere between 200 and 300.

Original downpipe with catalyst. Got perfect emissions one year ago.

I have tried to switch to another MAF, no difference.
Unplugged the lambda sensor, no much difference eighter.
Oil was changed not many miles ago.

I have no check engine and the engine runs smooth. It does smell like it's running a bit rich though.

The car has a Ecutek remap by Trollspeed. The only thing that's different compared to previous MOT is that I have installed a Hybrid FMIC. Could it really mess up the emissions that bad? I'm going in for a remap in a month but I'm afraid there might some other problem.

Could it be a faulty coolant sensor for the ECU? Or intake temp sensor?

Do you have any ideas?


Thanks


/Juha