In Reply to: Passing CA Emissions posted by Eric Fowler on March 03, 2000 at 11:20:26:
We're just taking stabs in the dark on this one. My 88 735iL with 226K passes at the same readings I got in 1992 with 112K. These are usually not that hard to pass. So, under the guise of having something else checked out, like and oil and filter change, take it to the dealer and have them read the fault codes from the diagnostic port.
If you insist on trying to slug it out alone here is a list:
Air and fuel filters
Spark plugs and wires.
Do the V-12's have hydraulic lifters? If not, adjust.
Check the fuel injection rail pressure.
Check for vacuum leaks.
Check position sensor (crankshaft).
Check the air box flow meter.
Pull one injector and take it to a specialized injection service shop and have them test it for leakage and spray patern. Although one bad injector will knock you out of an E test, on high mileage cars they all degrade pretty much the same. You can, also hit the injectors with the "bomb" like the dealers do (injector system flush).
If it points to the cats, I have pity on you. You might have to buy a ranch in Montana to establish residency and register it there. It would be cheaper than tackling that exhaust system!!
Looks like a long weekend,
John 88 735iL (226K)
79 320i (250K)
As I recall, the 88 750 O2 sensors are a bear to get at.
: My 88 750 is not even coming close to passing emissions. Besides taking it to a dealer and paying out the wazoo, what are my other options? I am thinking of doing plugs/wires b/c it probably needs them anyway. Any other suggestions? It is supposed to have new O2 sensors. It was my immpression that Cats were either 100% good or 100% bad, no in between. Mine have not overheated or clogged up so could these really be the cause? Any help would be appreciated. Thanks.