does anyone know what this code means?

 

One of your O2 sensors is not heating up, possibly one of the 2 sensors after the catalytic converter (Bank 2).

Our cars have 4 O2 sensors: 2 before the catalytic converter and 2 after. Each sensor has 4 wires going to it, one pair for the sensor reading and the other to heat it since its operating temp needs to be 300degC.

The problem is either a bad connection to the sensor or the sensor itself needs to be replaced.

 

Thank you so much!

If I examine the o2 sensors/wires, is there a way to tell which one needs to be replaced?

 

The heater circuit for post-cat sensor for cylinders 4, 5 & 6 is fubar'd. BTW, P0056 means "Heater Circuit Bank 2 Sensor 2." :str8pimpi

 

Since you just came from the dealership when it happened, they must have just sloppily reconnected the sensor harness connectors after servicing your car (did they do something with the fuel rail or intake manifold)?

The post-cat harness connectors are under the intake manifold cover, the one with the 7 stripes in the middle of the engine bay. Take out the microfilter housing first (search for DIY). After removing the cover, you'll see the two post-cat O2 connectors laid down horizontally.

Clean, remove then reconnect making sure the connections are tight. Easy DIY, not sure if it will fix your problem but at worst you'll only lose 20 min of your time.

 

What's that microfilter housing? Can't find DIY.

 

My stick shift was hanging up in 5th gear so they replaced the bushing pins iirc. Not sure what kind of engine work that would entail but I think they had to take some things apart.

The post-cat O2 connectors are in the engine bay. These run down underneath the car to the post-cat O2 sensors. You want me to check the connectors. Is this correct?

Also, what does Heater Circuit Bank 2 Sensor 2 mean? Is it referring to a specific O2 sensor and if so, which one?

Thanks for all the help guys!!

 

The post-cat O2 connectors are in the engine bay. These run down underneath the car to the post-cat O2 sensors. You want me to check the connectors. Is this correct?

Yes, just a hunch. It might be a long shot but at least it's free.

Also, what does Heater Circuit Bank 2 Sensor 2 mean? Is it referring to a specific O2 sensor and if so, which one?

Bank 1: Cylinders 1-3 (first 3 cylinders at the front of engine if I'm not mistaken)
Bank 2: Cylinders 4-6 (last 3)

Sensor 1: Pre-cat (this I'm sure)
Sensor 2: Post-cat (this I'm sure)

So the "Bank 2 Sensor 2" should be the post-cat O2 sensor for cylinders 4-6. The connector would then be the one towards the rear, if the bank sequence is correct as I understand it.

 

that is awesome info man! and yeah hopefully it is just a simple re-connect issue.

how long would it take for ses light to turn off?

thanks again

 

Prob. gonna take about a week to let it go off by itself.

If you have the OBDII tool, try turning it off. If it's still got a problem, it will come up again after about 2 driving cycles (or sooner)

if you don't have the tool, take it back to the dealer.

 

well i checked the connections under the right fuel rail. reconnected it and they seemed fine so hopefully the SES light will go away. is it particularly bad to drive around with this error code?

 

Have it reset first. If it goes back then most probably you need a new O2 sensor.

 

I checked all the wires and had it reset. SES is still lighting up so I think I may have to change the o2 sensors.

Has anyone tried doing this WITHOUT ramps?

 

thanks. should i go ahead and replace all 4 in one shot? i have about 75k miles on the clock. is it due for replacement?

 

According to the Bentley manual, they are all supposed to be replaced at 100k. I replaced all of mine at that mileage, not difficult but a little bit of a pita, especially the post cat ones. I would replace all of them at once, certainly if you plan on keeping your ride for a while and if you DIY.

--D

 

do i need to replace all the wiring along with the o2 sensors?

 

No..if you buy them from a reputable source like Bav auto, the wiring and plugs are included.

--D