Ok so I have some issues with my oxygen sensors lately!

I have replaced all of my oxygen sensors with Herco replacement sensors. Three of the error codes went away except for bank 2 position 2.
I have replaced the oxygen sensor now with a OEM sensor, thinking that the replacement sensor wasnt working. I am getting voltage to this sensor.

Also I have changed the crank shaft position sensor and the secondary air injection pump.

I am getting codes for bank 2 position 2 with the secondary air injection pump code also. I checked all fuses and are ok. I checked the cpu boards and cleaned the connections. I had also taken apart the EGR valve and cleaned the carbon off of the valves.
I check the voltage to my MAF sensor and am getting 5.46 V

Any other suggestions.

 

Ok so I installed the new OEM oxygen sensor, reset the CEL light and drove the car for 85.0 miles. I turned the car off and then went back into car and turned it on, CEL light turned on again. Computer is saying it does not see Bank 2 sensor too circuit. I checked the voltage across sensor and it is getting voltage. Any ideas?

 

You need to get a code reader that can show realtime data. I think most do. If the ecu is not getting a signal I would start buzzing out the wiring. If it is but seems different from the voltages sent from the other rear sensor, then you should check out the cat convertor. Seems like you are troubleshooting savy good luck.

 

Ok I put another 30 miles on my car and no change with the CEL. I am still getting a P0161 code (O2 sensor heater bank 2 circuit 2) . This is using the newest O2 sensor that is OEM direct replacement. I used my scanner and am getting B2S2 0.465v AND B1S2 0.460v

Also B1S1 0.890V B2S1 0.725v when running
I ran a live feed on B2S2 and am getting between 0.460-0.465V. The computer seems to be reading the sensor but the CEL is still going off due to this? Should I try new air filters.
So far i Have replaced all four sensors, crank shaft position sensor and secondary air pump, and replaced the new B2S2 universal sensor with a OEM sensor thinking that would be the issue. Any further suggestions? Thanks for your help Tunaglove. My inspection expired and even got my car impounded because of expired inspection and am trying to get this issued resolved asap and just cant get this one without help.

 

I just sprayed my MAF sensor with cleaner to see if that will make any difference?

 

The ecu does not see the sensor heater pulling the right current. Make sure the connectors by the transmission are not soaked in tranny fluid. Double check your wiring, look for shorts. Is it possible you swapped the connectors when you replaced the rears?

 

I didnt switch the back wires up because i replaced one at a time on different days so I didnt cross the wires. There is some transmission oil that is covering the outside of the connector. I did not see any oil in the connection itself, but i guess it could of possibly traveled up the back through the wires. Tomorrow i will spray the connection with brake fluid to clear all the oil out and degrease the bottom of the car. I will update you tomorrow with the results. Hopefully this does it, because i have changed out 2 new sensors already.

 

Another quick test you could swap the sensor connectors between the rears and see if the heater failure code goes to bank one. If it stayed on bank two then you would know for sure you have either bad connections or a shorted wire somewhere between the ecu and the sensor.

 

Check fuse #2 in the Relay Control Module. This should send 12vdc to the O2 sensor heater. If that's good unplug the 2/2 sensor plug and see if you are getting 12v to pin #1.

The schematic is on page 8W-30-7 and page 8W-30-10 in the document section service manual.

 

Ok so I sprayed the connectors with cleaner and then de-greaser so the plugs should be clear of grease. I Ran the Car and the Voltage to S2 Bank 2 is 0.460-0.465 S1Bank 2 is 0.555V after all the connections were sprayed. I cleared the CEL and will check to see if the CEL illuminates again.

Fuse 2 In the RCM is not blown so it seems good. I will check the sensor plug tomorrow and see if I get 12v to the unit. It was a bit snowy tonight, working outside so will have to wait until tomorrow to continue with the plug check. Thank for all your help tunaglove.

Oh and cleaning the MAF sensor with cleaner didnt work from yesterday CEL light turned on again.

 

Ok so i cleaner the plugs and ran it for a while with no success. I also cleaned all the connectors at the RCM and did no change. In the past the relay on my module would get carbon on the contact. Could a bad Relay control module work 3 oxygen sensors and not another? In other words could a bad RCM make just one sensor not work? I noticed a small burn on my RCM which may control the secondary inject pump but not sure

 

The RCM just controls the high power to the pump not the O2 sensors. It is the high power that burns the contact so easily.

 

Do you have an exhaust or intake leak? You've checked most everything else already. My car is throwing a P0161 too. It comes on when I start the car. If I clear the code and restart it stays off no matter how long or what type of driving I do. Shut the car off for a while and restart and it's back. When I find out what's causing it I'll post my solution.

Les

 

I am going to check next for exhaust and intake leaks any other suggestions i can test. I looked over all the vacuumn lines and everything looked ok. Is there an easier way to check for an intake leak?
This is the burn on my RCM i was mentioning. It seems like my b2s2 voltage stays only between 0.465 - 0.460v yet all the other sensor voltage bounce around when running. Its like my sensor is getting power but possibly not enough?

 

Les I am having the same issue with mine when i turn off and turn car back on too

 

bullish!t learn to read schematics before posting

 

Dude, the next step is to verify 12 volts pin one on your sensor connector. You have an o2 heater problem.you can check it key on engine off.

 

tunaglove , when you say check the pin? Do i disconnect the sensor from underneath the car where i plugged it in and stick a volt meter into one of the connection holes and check for voltage. Do i put the black probe in one hole and the red probe into another connection. If i dont get 12v what would be the next step?

 

Yes disconnect the sensor and red probe into pin one. If you look really close with a flashlight you will see the pins are numbered. The wire color should be red with dark green stripe. The black prob needs a good ground like your trans. If you are getting 12volts there we must ohm out the wire going back to the ecu heater side. This is a four wire sensor 2 for heater 2 for lambda.

 

Sorry, you are correct I should have double checked this, I just went by memory.