rear o2 sensor problems - need help
Thread Starter
Senior Member
Joined: Jun 2005
Posts: 470
Likes: 20
From: Houston, TX
2017 S63
rear o2 sensor problems - need help
Hey Guys,
My rear o2 sensor keeps giving the same error no matter what 02 sensor i try (i have a couple of them laying around, some new non oem and the originals that i took out at 100K miles).
I get P0161 which is heater circuit, and P0170 which is trim Fuel Trim Malfunction.
My air mass sensor is relatively new and the car drives well (I can tell I get good gas mileage, and I've owned it long enough to 'feel' when its not running spot-on"
So I am suspecting wiring problems maybe or maybe a fault in the computer??. Before I go and investigate, does anyone have any experience in a common failure? The 02 connector looks good with clean contacts and mates well, the wires up into the harness near the transmission pan also look in good shape.
anyone got any good trouble shooting tips?
thanks in advance
Jim
My rear o2 sensor keeps giving the same error no matter what 02 sensor i try (i have a couple of them laying around, some new non oem and the originals that i took out at 100K miles).
I get P0161 which is heater circuit, and P0170 which is trim Fuel Trim Malfunction.
My air mass sensor is relatively new and the car drives well (I can tell I get good gas mileage, and I've owned it long enough to 'feel' when its not running spot-on"
So I am suspecting wiring problems maybe or maybe a fault in the computer??. Before I go and investigate, does anyone have any experience in a common failure? The 02 connector looks good with clean contacts and mates well, the wires up into the harness near the transmission pan also look in good shape.
anyone got any good trouble shooting tips?
thanks in advance
Jim
Senior Member
Joined: Feb 2010
Posts: 271
Likes: 0
From: Minnesota
Mars Red 2005 C230k, 2001 E320 4matic
I seem to be having similar problem only on the drivers side. No one seems to have a clue what to do. Although I would always recommend replacing 02 sensors with oem parts. Mine is also running rich on short trim, with cylinder misfires on all cyinders drivers side. On the bad side everyone keeps preaching, cats, spark plugs, and 02 sensors. You can find them at fairly cheap. I now ohlord sells them for a damn good price.
Last edited by Brau0318; Nov 26, 2010 at 03:09 PM.
