Volvo S80 multiple misfire codes and misfire codes on all cylinders.

Axe · Post by **Axe** » 17 Dec 2016, 10:16

Hello!

I have a 2002 s80 t6 with about 150000 miles on it. I am having some codes being thrown along with a rough/low idle. The codes are as follows
P0236
P0056
P0161
P0130
P0300
P0301
P0303
P0302
P0305
P0306
P0304
P0171
P0128
P0160
P0156

I know, quite the list. Believe it or the not the car actually runs great, minus the rough idle and poor gas mileage. I've checked plugs and bank 1 is running rich and bank 2 plugs are perfect looking which leads me to believe the o2 sensor is actually bad on bank 1. Could this be causing misfires? I checked for vacuum leaks and cannot find any. I do not get any suction or white smoke out of dipstick which I've heard can be associated with vacuum leaks? I have read that a dirty etm can cause a rough idle, is this worth looking into? I also wonder why I am getting a turbo low circuit code? I have cleaned the map sensor but have not replaced it. I have not replaced the maf sensor but I did clean it. Not sure if this all could be related to one problem or not? The low coolant code I'm pretty sure was thrown when the car was running and sprung a coolant leak on the thermostat housing ( stupid brittle elbow). Any help would be aprriciated, thanks!

Post by **abscate** » 18 Dec 2016, 18:19

Clear the codes and see what comes back first. That's much better guidance for troubleshooting

Axe · Post by **Axe** » 19 Dec 2016, 11:08

Thanks for the response! I have cleared the codes and this is what came back. I'm really doubting just changing the o2 sensor and plugs will solve my problems. Which is the only thing I can see from the codes that is registering as bad. Just looking for advice as to what my next step would be.

ThommyKent · Post by **ThommyKent** » 19 Dec 2016, 13:21

All your codes except 2 or 3 are O2 Sensor or Catalytic converter codes. Those two things work with each other. Do the 02 sensor/s Then see what happens.

Axe · Post by **Axe** » 19 Dec 2016, 18:57

Did the bank 1 o2 sensor 1 and plugs tonight and noticed a big difference. Idle smoothed out and is no longer running rich. Will clear codes again tomorrow and see which ones come back. The turbo circuit low code was the one I really wasn't sure about. I didn't know if this one could be caused by a faulty o2 sensor? I'll see if that one comes back or not. Thanks for the responses!

Axe · Post by **Axe** » 26 Dec 2016, 18:40

Cleared the codes and this is what came back

p0236- turbo boost sensor a circuit performance range
P0237- turbo boost sensor a circuit low
P0161- o2 sensor bank 2 sensor 2 heater malfunction
P0056- o2 sensor bank 2 sensor 2 ho2s heater control circuit

I'm thinking I just need to replace the bank 2 sensor 2 o2 sensor and that will clear 2 codes. I'm not sure how to proceed on the boost performance issue? Is there anyway to test the map sensor? Anyway to test pressure in the intercooler? Anything else I should be checking? Thanks!

Axe · Post by **Axe** » 02 Jan 2017, 16:13

Replaced bank 2 #2 o2 sensor, map sensor and codes have cleared themselves. Downstream sensor is a pita to change without dropping the exhaust.

ThommyKent · Post by **ThommyKent** » 03 Jan 2017, 03:09

Thanks for telling us your results

Axe · Post by **Axe** » 03 Jan 2017, 16:24

No problem. Always a bummer reading a thread and not knowing how it turned out.

Axe · Post by **Axe** » 04 Jan 2017, 17:20

Thought I was in the clear but 2 new codes have come up.
P0422- catalyst 2 efficiency below threshold bank 1
P0432- catalyst 2 efficiency below threshold bank 2

I haven't replaced the bank 1 #2 o2 sensor but all others are new. Is it common for the cats to go bad in these cars? Car still runs great and is getting good gas mileage. Could it have been caused from the car running rich?