MZen

Hi,
I got P2A00 code on 2009 R320 diesel.
My code reader says "O2 Sensor Circuit Range/Performance. Bank 1 Sensor 1"

I purchased Alldata subscription recently, yet there is no information there about this code. I can change O2 sensor myself, but which one? Where is Bank 1? Is it really about O2 sensor or related to something else?

Has anyone experienced such problem and what was the solution?
My situation complicated by necessity to pass emission test by the end of the month. Here in Canada it is done by reading codes, so my R will not pass it in present condition.

Help!
Any help is greatly appreciated!

Plutoe

First have you erased the fault------------if yes, has the fault returned??

MZen

I have erased a code (different one) and was driving to get Readiness Monitors ready for emission test.
Little bit afraid to erase it again, since I do not have enough time for Monitors.

auto385

Bank one means the cylinder head that is the most forward of the 2 heads. Sensor 1 means the upstream oxygen sensor. You will have to erase the codes anyway after instalation of the sensor. You should be able to run all but one monitor within 30-50km. If you want to tackle this yourself, you should at least install an OEM part as an aftermarket part may give too big a range and in effect set another code.

MZen

Thank you for reply.
Visit to dealership confirmed only one O2 sensor on R320.
Price range:
520+HST at dealership
the same Bosh - at Exoparts (Toronto) - 360+HST
the same Bosh at MAT - 420+HST
aftermarket - 280 at MAT
120 at Tec Comp. Got it with 1 year warranty, 14 days replacement. Never seen before warranty on computer/sensor components.

Will try.

UPDATE:
cleared the code and it did not return. Drove all day yesterday and passed emission this morning. Good to go for two more years!

Going to return O2 sensor.

dave2001auto

If your oxygen sensor is bad, it will reduce the fuel economy and may damage the dpf, cat and/or engine.
Bosch makes the AFR sensor for Mercedes.

The Bosch AFR sensors are Under $150 at FCPEuro in the US. FCP warranty is for owner’s life.
Amazon is about $40 less with questionable year warranty of one year. Some Credit cards extend it to two years. I got one on Amazon for $50 once.
The AFR should last over 150,000 miles but don’t even come close in the bluetec.

Menti

It's amazing that no one actually helped but one bloke jumped with his problem in the middle of the thread and after finding his solution whole thread is dead!
I want to know the solution to the original problem as my S600 has exactly the same issue... ANYone?