Took my car off for an MoT and it's failed on the emissions side of things. Namely the hydrocarbon, CO is fine sitting in at a nice 0.868. Anyone got any idea why my hydrocarbon would be so high? It's like 6410 and the max is 1200! :wack:

HC is unburnt fuel, caused by misfires, incomplete burning in the cyl.

 

1 point to note is that if a non cat test fails on HC at idle (but CO is within limits) then the HC should be retested at 2000rpm. if it is under 1200ppm (& it prob will be!) at that speed then the vehicle would pass the emissions test ;)

HC is unburnt fuel, caused by misfires, incomplete burning in the cyl.

 

1 point to note is that if a non cat test fails on HC at idle (but CO is within limits) then the HC should be retested at 2000rpm. if it is under 1200ppm (& it prob will be!) at that speed then the vehicle would pass the emissions test ;)

Well the car as had it's carbon canister removed and the AIV junked and the water temp sensor seems to work when it feels like it. I guess that would have affected it?

 

So would replacing the O2 sensors be a good idea? Maybe even junking the cats too while I'm at it as I'm sure at this rate it's prob completely shot due to the high HC levels.

 

Any advice would be great as I need to make a list of things to do before summer!