RMarius

Hi,

I start by saying this is my fault for not disconnecting the battery before messing with the EGR valve (passenger side top of the engine block in the rear)
The 2005 E320 is not a daily driver and once in a while I take it around the block.
While trying to remove the EGR valve I dropped a wrench that got logged for a couple seconds between the Starter and the O2 sensor.
Don't ask me how.. It did make some nice yellow sparks before I move it out of the way.

Sure enough I got a P0410 (Secondary air injection) code a day later on a cold day, but I don't think its related to the air blower.
I am thinking to replace the O2 sensor (Bank 2 sensor 2 I think, passenger side closest to the exhaust headers, and next to the starter) but I also noticed that there is no fuse and that it goes directly into the ECM
A bit concerned that I #@$ up the ECM ? Is that possible.

Any thoughts are appreciated. Is there a fuse ? I don't have a wiring diagram but I don't think its connected to the blower in anyway.
Its worth mentioning that the ODB2 computer says ATHMOS when reading values for the O2 sensor... I don't recall seeing 4 sensors on the diagnostics.

Thank you

F1Fan

I think you killed the O2 sensor. Secondary Air system relies on the O2 sensor to check if the Secondary Air Injection system is working properly. If the computer does not see the O2 values change when the pump is running, it throws a P0410 code.

I would replace the O2 sensor. But make sure you get a quality Bosch or Factory one, not some cheap aftermarket one.

RMarius

Thank you. I took that O2 sensor out and getting 9.5 Ohms resistance and 1.xx Volts when I heat it up. Will check O2 on the other side to see if resistance is different. While I'm doing this, is there a fuse or relay I should check for the air pump ? (A0001403785) or is there a way to test it while its removed ?