O2 Sensor S70

rameeler · Post by **rameeler** » 23 Dec 2011, 14:46

Hi All,

I have a 1999 Volvo S70 AWD Turbo that I just bought. The car has its check engine light on and is shooting out the following codes: P0036 (HO2S Heater Control Circuit Bank 1 Sensor 2), P0135 (Bank 1, Sensor 2), P0014 Exaust Camshaft Position Timing. When the car idles it throughs out a lot of smoke of a whiteish color, it comes in big puffs everytime the car is stopped.

I took it for inspection and the only code that failed my emission test was the P0036.

What do you guys think the problem could be? What parts are needed?

Thanks for all the help, im new to this site

I have tried posting im not sure if it goes through or not

Post by **Ozark Lee** » 23 Dec 2011, 17:18

The P0036 is the heater on the O2 sensor which is either a bad sensor heater or a bad connection to it. You can check the sensor heater with an Ohmmeter (out of circuit, as in unplugged). It should have fairly low resistance. If it comes back as an open circuit your only option is to replace the sensor. The heater wires are the white wires.

...Lee

AdlerV70 · Post by **AdlerV70** » 23 Dec 2011, 18:31

I read somewhere on here that the resistance should be around 3 ohms.

rameeler · Post by **rameeler** » 27 Dec 2011, 20:47

Is the heater element separate to the o2 sensor or is it the same thing?

also should i take it too an offical dealership and pay $150 to diagnose, or should I just go ahead and replace the o2 sensor from my personal mechanic who will charge me $400 for the whole job.

THanks

Post by **Ozark Lee** » 27 Dec 2011, 21:30

The heater is built into the sensor itself so if it is bad the entire sensor needs to be replaced.

...Lee

AdlerV70 · Post by **AdlerV70** » 28 Dec 2011, 06:28

The sensor is very easy to replace. As simple as replacing a bolt. The only trick is that you need a special O2 sensor socket which is usually just a deep well socket with a groove cut up the side to accommodate the wires sticking out the back of the sensor. Just unclip the harness, back out the sensor, screw in the new sensor, reclip the harness and you're done! Of course, this is assuming access is not a problem...

Post by **jblackburn** » 28 Dec 2011, 11:25

Spray the sensor threads with a TON of PB blaster a few times before attempting to unscrew it.

Mine came out with a good whack on the wrench, but people with northern cars have had some real difficulty getting them loose.

If all else fails, heating it with a torch can work as well.

Post by **boosted5cyl** » 29 Dec 2011, 13:55

My advise would be to resolve the exhaust cam timing code and the white smoke before you replace the sensor. Chances are the code for the O2 sensor is due to it becoming contaminated. If you just replace it, you may end up just contaminating a new one.

turbozutek · Post by **turbozutek** » 30 Dec 2011, 03:04

boosted5cyl wrote:My advise would be to resolve the exhaust cam timing code and the white smoke before you replace the sensor. Chances are the code for the O2 sensor is due to it becoming contaminated. If you just replace it, you may end up just contaminating a new one.

+1 on that.