m40 running rich???

[raybk92]

hey guys I've got an 89 318i, the engine is an m40 and around the exhaust there's a build up of carbon so I'm guessing its running rich??? Would the cause of it be oxygen sensor?, air flow meter needs to be recalibrated?.....can you please help me cause I'm only getting 350km to one tank and its really annoying me....
Thanks

[jasonbk]

I posted same problem couple weeks ago and I was told that the standard check would be fuel pressure, O2 sensor, coolant temp sensor, and exhaust leaks. Hope it helps.