In Reply to: O2 sensor replacement on 535i, need HELP posted by Getting bad MPG! on March 28, 1999 at 06:38:26:
: I am getting no more than 15 MPG on my 89 535i, city driving of course. Recently had her serviced with new plugs (Bosch +4 plat.), wires set, cap'n rotor, valve adjustment, Mobil 1. The car seems to have no other problems. Smooth idling, smooth acceleration. Why 15 MPG? I drive very conservatively. My right foot is very light.
: What's next? Want to replace O2 sensor by myself. Is it possible without special tools? Is there just one near the Cat and no more? Some company sells the 'O2 senor Kit', which replaces just the core (i guess that is the sensor). is that good? it sounds better to replace the whole unit. anyways. any comments or advises will be appreciated.
I also get this 'rattling' noise under the car whenever I put it in 'R' reverse. Only when the car is warmed up. when cold coming out of a parking spot, no noise smooth no problem, but after driving a bit and want to go on 'R', that rattling under the car comes back. Rattling seems to disappear when the car is in motion, but coming out of a parking spot slowly with no gas, i get the 'rattling' The car is fine in any other gears. any ideas???