Originally Posted by andy777
Plugs, maf's, pre cat o2 sensors, air filters, injection clearner, check the battery.
36k miles you say?
your plugs are functional, but way off peak efficiency...if not at end of useful life.
your MAFs are functional, but not running at peak effeciency.
your O2 sensors are probably still pretty good, but at 36K they're probably getting "lazy."
you should be changing your air intake filters yearly. more frequently if you live in a dusty/etc. environment.
fuel injector cleaning also a good idea.
a battery strength test also a good idea.
you should also be changing your cabin air filters yearly unless you like bad outdoor smells, pollen, and a musty HVAC system.
at 36k I'd also be seriously looking into changing my fuel filter. I'm sure she's cloggin up by now and stressing your fuel pump.
be advised that all of the parts needed to do the above (besides FI cleaning and battery) can be had online...well in USA anyway...for $270 and can all be DIY'd.
Erase the BMW service interval recommendations from your mind.