850i - Running rich

Okay, so I'm planning on buying an 850i off craigslist hopefully in the next month if things go well money-wise. Anyways the guy selling the car just tried to get it aircared (smog test) and it failed because the passenger side of the car is running really rich, he's changed the O2 sensor and all the intake gaskets on the engine. Could this be an electrical problem? Any suggestions in to why it is would be great. And also, he doesn't have the middle dash, the obc screen, how hard is it to get one, and how much is it going to cost? Thanks

Bump

Mass Airflow Sensor, DK motors needing cleaning and rebuilding
I would start with these two things first.

Originally Posted by TxGr8White

Mass Airflow Sensor, DK motors needing cleaning and rebuilding
I would start with these two things first.

Okay, I understand the mass airflow sensor, but what are the DK motors, sorry lol

throttle motors.

what were the readings of the gasses?? rich indicator is co, while hc is an indication of misfiring. if they do a nox test, then that would indicate cats as there are no egr valves on the m70.


df

Turns out to be a faulty cat, but I'm not buying this car anymore, it's nice and all but it's a 4 speed

Originally Posted by cmellios16

... it's nice and all but it's a 4 speed

...with little effort is is a very fast 4-speed...