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bank 2 sensor 2?...help!

11K views 21 replies 5 participants last post by  GOPHERIT 
#1 ·
My 2008 G8 Gt is throughing a bank 2 sensor 2 code on my Altron scanner. Dealer says it is the upstrem pass side, but I thought it would be the post cat pass side. I swapped the to post cat sensors and still got the same code so I replaced the upstream pass side o2 like dealer suggested...but not not fix. Still getting a Low Voltage Bank 2 senor 2 code. Any help would be great...THANKS!!!!
 
#4 ·
Getting that fault code posted would be best. Then the members could help you dial in the the bad guy here. I did not read that you even reset the fault code prior to testing/changing things. So if you did not perform a reset with the code reader, or disconnect your battery for a short period of time to cause the same thing,It would take at least the 4th start/drive cycle to have the ECM cancel that MIL light. An it would only do that, if the car passed its self check of the HO2 sensors on the previous 3 cycles.
If you've gone thru several start/drive cycles since the swap and replacement maint you performed, and you still have the MIL light, you just HAVE to find out what that fault code is. Otherwise, you will continue to shotgun the problem.
 
#8 ·
the car has long tube Kooks and kooks high flow cats with full cat back Kooks. The exhaust and tune has been on the car @ 10,000 miles. Car now has 62,000 miles. All wiring appears to be free of exhaust heat.
I could do a check on the harness if I knew the steps...
 
#10 ·
Take in and get it diagnosed, If the code is what I think it is you might need a ecm. It supplies the proper voltage to the o2. It also could be the pins in the connector are spread and not creating good contact. But if you have a tune you should not even be getting a code for a #2 sensor.. most tunes stop the computer from monitoring that sensor all together.. So yeah like I said take it to your tuner and or shop..
 
#11 ·
The wiring can be checked some by doing this>>>> With power off, pin A at the disconnect goes back to the ECM and is grounded internally. It says you want to see less than 5 ohms from pin A to any convenient ground source close by.
If I understand this correctly, with the ignition in the *on* position, you should read about 450 mv on pin B when going to ground, or back thru pin A.
Pin C goes back to the ECM and is triggered to become a ground, whenever the ECM says so. It becomes the return path to ground, for the heater circuit within the sensor (pretty sure the engine has to be running to set that ground).
Pin D at ignition turn on, is supplied with 12 vdc to power the heater. If you get some good numbers from this, you might be able to eliminate the ECM

Not knowing what goes on with sensor placement with LTs installed, is it possible that extension harnesses had to be installed (which would add even another connector in the loop) ?
The dealer could hook up the scan device, an perform a lot of checks to verify the operation of this circuit, but if they are locked into the upstream sensor as the problem (an you now know better), it might become a no joy situation, and money also being pulled from your wallet.
The T/S you have performed seems to have eliminated the sensors as being the bad guys here.
 
#15 ·
Thanks for the write up but how do I know what the pin positions (A,B,C,D)are on the connector?
thanks

The wiring can be checked some by doing this>>>> With power off, pin A at the disconnect goes back to the ECM and is grounded internally. It says you want to see less than 5 ohms from pin A to any convenient ground source close by.
If I understand this correctly, with the ignition in the *on* position, you should read about 450 mv on pin B when going to ground, or back thru pin A.
Pin C goes back to the ECM and is triggered to become a ground, whenever the ECM says so. It becomes the return path to ground, for the heater circuit within the sensor (pretty sure the engine has to be running to set that ground).
Pin D at ignition turn on, is supplied with 12 vdc to power the heater. If you get some good numbers from this, you might be able to eliminate the ECM

Not knowing what goes on with sensor placement with LTs installed, is it possible that extension harnesses had to be installed (which would add even another connector in the loop) ?
The dealer could hook up the scan device, an perform a lot of checks to verify the operation of this circuit, but if they are locked into the upstream sensor as the problem (an you now know better), it might become a no joy situation, and money also being pulled from your wallet.
The T/S you have performed seems to have eliminated the sensors as being the bad guys here.
 
#16 ·
Car sounds very nice..nothing but compliments, you will not be disapponted!
Although it does have a droan at cruising speeds.
High flow Kooks cats, no resonators and no xpipe.
Sorry...dont have a video clip

Do you happen you have a video of your car I'd really like to hear how it sounds with the kooks High flow cats and mufflers. How is the x pipe set up, any muffler or resonator or just straight?

Car sounds very nice..nothing but compliments, you will not be disapponted!
Although it does have a droan at cruising speeds.
High flow Kooks cats, no resonators and no xpipe.
Sorry...dont have a video clip

Sent from AutoGuide.com App
 
#14 ·
Wait a sec, you have Kooks long tubes and high flow cats and an aftermarket tune? This changes things! I'd start with the tuner and find out why the post cat o2's weren't just turned off? I've never heard of any one keeping the rear o2's on when you have headers and high flow cats. Just go back to the tuner and have them turn the rear o2's off and you'll never have this problem again.
 
#17 ·
I bought the car already setup this way 3 years ago. I agree, figured they would have tuned out the O2 post sensors but why re-install and get extentions if they where tuned out?...most the time they are just Bugged off.
I'll do some more checking of the connections and pins...if all good then probably just get a new fresh dyno tune and delete out the rear O2.
Thanks


Wait a sec, you have Kooks long tubes and high flow cats and an aftermarket tune? This changes things! I'd start with the tuner and find out why the post cat o2's weren't just turned off? I've never heard of any one keeping the rear o2's on when you have headers and high flow cats. Just go back to the tuner and have them turn the rear o2's off and you'll never have this problem again.
 
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