2000 s80 P0036 and p0136 codes

marcsanders · Post by **marcsanders** » 28 Feb 2014, 09:51

2000 S80 T6. P0036 and 136 codes (bank 1, sensor 2). Replaced both downstream O2 sensors with Bosch units. Still throws codes. Disconnected battery for 10 minutes, still throws codes. Idle is rough. Hesitates on acceleration. It has aftermarket plugs and a few aftermarket coils. No evident vacuum leaks. I have the voltage measurements from the scanner. They are identical on both banks, but I am not sure how to interpret them. The rich-ln and ln-rich thresholds are both 0.605 V. The min V for cycle show max 0.595, the min is 0 and the measured is 0.190. The max V for cycle shows max 1.075, min 0.615 and measured 0.720. I replaced the MAF sensor, removed and cleaned the throttle body, which solved the rough idle/acceleration problems and got rid of the 0036 code, but the 0136 code stays. Any suggestions? Thanks for the help!

Bluevanacd2005 · Post by **Bluevanacd2005** » 28 Feb 2014, 09:55

Some kind of fuel or air issue.

marcsanders · Post by **marcsanders** » 28 Feb 2014, 19:08

I spoke with my mechanic toady and he said that given the voltages, he thinks the problem is with the upstream sensors and recommends replacing those. He says info from the ECM goes through the upstream sensors to the downstream ones and if they are defective, it will throw the code for the downstream sensor (0136).

Bluevanacd2005 · Post by **Bluevanacd2005** » 28 Feb 2014, 19:49

Usually there is another problem when all (or two) sensors read bad though.

marcsanders · Post by **marcsanders** » 01 Mar 2014, 00:04

What kind of fuel or air issues do you mean? I replaced the Maf sensor and cleaned the throttle body. I have checked carefully for vacuum leaks. Do you have any other suggestions for what I can check?
Thanks.

jimp54 · Post by **jimp54** » 02 Mar 2014, 04:41

I thought I had checked my car for vacuum leaks also,sprayed carb cleaner on everything that had a vacuum hose.Wasn't until I had a "smoker" hooked up did I find about 5 major leaks,not all vacuum is at idle. It was well worth the $50 and the car can't run any smoother.Be surprised how much was coming out of the plastic turbo tubes,from removing them over the years they stretch and get small cracks.I took them off and did a nice neat job of wrapping electrical tape under the clamp areas,that sealed them up nice.And some black RTV sealant,thin coating on other hoses to help get a nice seal.Hooked up the smoker again and not a puff . I've seen where a guy took a piece of vacuum hose and blew cigar smoke into it and did the same thing,but it wasn't worth me getting sick over this car.
Also another thing I learned,replacing anything less than all 4 of the 02's at the same time will cause more problems.If 1 is going then the others are sure to follow,it gets a perfect reading and easier to do them all while you're under there anyway.

Post by **jkdjim** » 03 Mar 2014, 12:47

a smoke test is only $50? I might have to do that for mine

jimp54 · Post by **jimp54** » 04 Mar 2014, 06:47

Found a guy in a local garage,don't need a Volvo tech for it,just needs the machine and know where to hook it up to. Takes 10 minutes,he was glad to get the $50 bill.

marcsanders · Post by **marcsanders** » 24 Mar 2014, 22:48

I had the upstream sensors replaced. Still has the same codes. I'll try the smoke test.