xdanny510x

Does the way a rear 02 sensor sit effect pcm reading? Perhaps if its sitting upside down on pipe opposed to at a angle or on top of the pipe.

arthursc2

iTrader: (5)

It doesnt, except that water can collect on the sensor and give erratic readings. It should be mounted above horizontal as much as possible, to allow condensate to drip off and not collect

xdanny510x

Cauae im getting false readings.. check engine light goes on and off... and the dealer checked everything and thats the last option they are giving me

arthursc2

iTrader: (5)

How are the sensors mounted? I would be inclined to suspect the wiring or the terminals before I would blame the orientation, but I dont know for sure

00pooterSS

iTrader: (40)

Doesn't matter as far as the reading goes. Never really considered what arthur said about condensation, that's a good point.

What codes are you getting, what vehicle is it

1994Vmax

iTrader: (4)

Water will screw the readings up bad... you always want them angled so water cannot collect in them. Temp is also a problem but being heated they keep themselves in check. I deal a lot with stack analyzers in plants and it's the same principle and sensor type as a vehicle. That said side of the pipe or top and you are golden... just don't angle them towards the ground.

xdanny510x

sensor is mounted upside down on passenger side... all the others horizontal or at a angle...but the wires and sensors are new... pigtail is new on harness side... its resding the ohms and voltage... the ecu is good.. software is good.... the last resort is the way that the sensor is mounted..is wat the tech said

xdanny510x

p0157... comes and goes... gm re wired a new harness and everything tests goods.. its a 05 silverado

someotherguy

If you swap your rear sensors does the code follow the sensor or stay on that side?

Richard

xdanny510x

stays on that side..