robertbartsch

I got a PO133 code on my BMW. The OBD2 (ISO software) book says it is low voltage - oxygen sensor (02) Bank 1, Sensor 1.

This is a bad FRONT O2 sensor on the DRIVER'S side; right?

Thanks..


...cheapest one is $129 - what a rip off!

Purrvert

1-1 pre cat drivers side, 1-2 post cat drivers side
2-1 pre cat pass side, 2-2 post cat pass side
Shop around 80 bux ought to do it.

robertbartsch

Thanks...

robertbartsch

One other question - please.

Does a bad REAR O2 sensor usually indicate a bad cat convertor too? Doesn't U.S. Federal law require a car manufacturor to replace a defect cat free if the car is driven less than 80K miles?

I already replaced the passenger side cat in this vehicle a few years ago. ...BMW reliability SUX!

Thanks...

horist

If it's a Cat efficiency code then it could indicate a failed cat.... in which case it *may* be warrenteed (if they can show it was caused by running too rich or lean backfires, or a mod caused either then they don't have to warranty)

Also I believe the warranty is only 8 years?

a bad rear 02 however just means that... it's a bad O2 ... a rear O2 reporting poor Cat efficiency means a bad Cat

rkinney

yeah, GM warranty on catalytic converters is 8yrs/80,000. with some specific vehicles getting 10/110,000 to warranty converters. When a cat. becomes less efficient you can watch your post o2 voltages and they will begin to swing up and down like the front o2's do. The post o2 should read a stable signal. On a Tech 2 you can plot this and should be flat line. ex: .750 with little variance. They will usually toggle though until the cat is fully heated and functional.

felton316

Bank 1 actually refers to the bank of cylinders in which cylinder 1 is in. Fords, for an example list their cylinders differently so bank1 would be the passenger's side.

Is the BMW a V or Inline? Maybe a model would help.

robertbartsch

The BMW is a V-8.

I thought the Bank 1, Bank 2 designation was consistent from vehicle-to-vehicle. The fact that Bank 1 on a Ford is the passenger side spookes me out.

How could I check the designation of Bank 1 on a V-8 BMW?

Thanks..