Oxygen sensor problem, bmw blaming the cat.

[aarsavage]

My car went into BMW in November and they changed the pre and post cat sensors on bank 2.

I’ve just got another code, cleared and it reappeared within minutes.

P2415: O2 Sensor Exhaust Sample Error Bank2 Sensor 1

Took it back to BMW hoping it would be an easy warranty replacement, they said it wasn’t the oxygen sensor and that they’d need more time/money to look at it.

Got a call yesterday saying the "engine was all over the place” they had swapped the coils, plugs and injectors from bank 1 to bank 2, tested compression and the error is still present on bank 2.

He said the technician is 95% sure the catalytic converter is shot, and £1800 all in would see it replaced.

I’ve googled and I can’t find anything that points to the Cat needing to be changed in this situation.

Popped into an indi and he said he reckons it could be an air leak on the intake or the oxygen sensor itself is faulty, which makes way more sense to me. (but only bmw can change the part under warranty)

Are they pulling my pants down or could the cat be the cause?
Wouldn't the cat throw its own error code if the post sensor reading was far off the pre?

Any help appreciated, could really do without that repair bill right now.

[Smartbear]

Hi, there's a cat cleaning product (cataclean?) that I'd give a try before handing over £1800-from memory it's had good reviews.
Try doing a search on here for it
Try this viewtopic.php?f=2&t=84224&p=1416749&hil ... n#p1416749
Rob

[Scooba_Steve]

Here's an idea, screenshot the codes and replace the sensor yourself (think it's a pre-cat one). If problem solved, charge them for the new sensor and costs for them not resolving the fault.