"Oxygen O2 Sensor Circuit Low Voltage (Bank 1, Sensor 2)"
P0136

I'm assuming post cat lambda has gone up the swanny? - have a spare, so will swap it out as soon as it stops bloody raining.
Erased the code, and so far it hasn't come back so far...

Start of a list of generic codes here.

Low voltage just might/might just be a poor connection.

I had that fault come up with mine. Cleaned the sensor up and it never came back.

Assumed it was due to picking all the crap, roadsalt etc off the roads blocking the sensor and sending the misread to ECU

These sensors can malfunction if contaminated with ethylene glycol which is a component of antifreeze. It can be cleaned off, but it could be an early warning of head gasket problems.

There was also a big problem with them down here in the south several years ago, when one of the big petrol company's distribution tanks was contaminated with silicone. That can't be cleaned off and cars were 'dropping like flies' everywhere. There were so many that all the dealers and factors ran out of sensors and people were waiting weeks to get a new one.

Dave.

fingers99 said:

Start of a list of generic codes here.

Low voltage just might/might just be a poor connection.

Click to expand...

Kinda thought that might be the case - will break out the vaseline
My second sensor was re-wired from one I got off Kristian - so it's entirely possible that my electrician type skills have failed me
Will re-check the connections when I get the lambda off the car!

AppleSei said:

I had that fault come up with mine. Cleaned the sensor up and it never came back.

Assumed it was due to picking all the crap, roadsalt etc off the roads blocking the sensor and sending the misread to ECU

Click to expand...

what did you use to clean it?

Davren said:

These sensors can malfunction if contaminated with ethylene glycol which is a component of antifreeze. It can be cleaned off, but it could be an early warning of head gasket problems.

There was also a big problem with them down here in the south several years ago, when one of the big petrol company's distribution tanks was contaminated with silicone. That can't be cleaned off and cars were 'dropping like flies' everywhere. There were so many that all the dealers and factors ran out of sensors and people were waiting weeks to get a new one.

Dave.

Click to expand...

I had thought about that - hg went 13months ago, resulting in the head being skimmed and a new hg going on.
My compression results came out slightly lower (1bar) on the middle two cylinders than the outers - however, this (I am told) is not necessarily anything to be too worried about.
There are no obvious signs of hg failure, and the car generally runs very well these days - also the error code hasn't come back.
I also thought I would rule out hg failure since the second sensor only measures what's getting through the cat to determine whether it's doing it's job or not - but since I'le be going for an spi manifold and cat soon to replace my mpi mani-cat.....

ronnieronson said:

what did you use to clean it?

Click to expand...

i didnt, it was done when i took it for a diagnostic, i was told they cleaned it up and was only charged for the diagnostic (£30) and no replacement parts etc were on the bill.

Would assume some sort of injector/sensor cleaner and a cloth

hmm fair enough...

are you sure they didn't "clean up" just the sensor error code?

nmrmak said:

are you sure they didn't "clean up" just the sensor error code?

Click to expand...

The lambda lives inside the exhaust system - pretty sure Apple meant physically clean the sensor as opposed to clearing the DTCs from the ECU

a physical clean up of all sensors

If they had just cleaned up the code, and it came up again i wouldve gotten a free diagnostoc and a proper clean job out of them. Thankfully it didnt, and the car is still living on today with no problems so the job mustve been thorough