I have a 1996 E36 323i which has failed the MOT on emissions.
The car was showing fault codes on both Lambda sensors and the MAF. These have all been replaced and all fault codes cleared but the emissions are still way out (CO=4.5%, HC=480ppm, Lambda=0.85). These have improved a bit since replacing those sensors.
Does anyone have any idea what could be causing this? I suspect possibly a misfire or coolant/air temp sensor but no other fault codes are showing.
Is there an easy way to test coils/misfiring?