I changed my timing belt on a 740 GL Sedan recently..
after many frustrating hours trying to get the car running again (ahould have been simple enuf) I discovered (through this website) that the car has an on board diagnostic system!
This computer told me that the RPM sensor doesn't work- so I went to the local junkyard and found two- and apparently neither of them work - then I bought one from an alternate yard for $45 (no returns) and that one didn't work- so i bought a spanking new one ($60) and that one seems to work - although the same thing keeps happening..the car starts but won't run for long.. and the computer tells me that the RPM sensor is not working...
so how does one reset the comnopuyter so that it will recognize a new sensor?
and why can't I get the car to run evenly? the engine sounds like it's laboring and it runs very rich- you can hear it puff and cough slightly- all the plugs seem to be firing. I inspected the inside of the intake where the air mass sensor is and it was all black-
any help woudl be appreciated

thanks