O2 sensor

[Omega Nige]

Hi, on my 3.2 I keep getting a warning light o2 bank 2 sensor 1. Where is it on the exhaust? I clear it and it comes back on when crusing at about 40mph.

[TheBoy]

Pretty standard for either Bank1 Sensor 2, or Bank 2 Sensor 2 to do this on 2.6/3.2.

Solution is to move the sensor from its current location between the starting cat and the main cat, to after the main cat.  This is achieved by welding in a new boss into the cat section, after the main cat, and moving the sensor, and plugging the original sensor hole.  Bosses with plugs are only a few quid, though its possible you will struggle to remove the old sensor, so might need to abandon that in place, and put a new one in the new boss.

Then reset the codes one last time, and problem solved. Forever.

[Doctor Gollum]

Hi, on my 3.2 I keep getting a warning light o2 bank 2 sensor 1. Where is it on the exhaust? I clear it and it comes back on when crusing at about 40mph.

Use a tank of Shell V power, a couple of cans of Wynns fuel treatment and drive it like you stole it. If you get over 240 miles out of the tank, then you're simply not driving it hard enough.

Driving in top at 40mph is guaranteed to put the light on.

It needs to be driven firmly to keep the P0420/0430 at bay. Those codes are factory fitted, so they will appear periodically, but less if you actually drive the car and more if you pootle everywhere.

[TheBoy]

That can help hold them at bay for a bit, but ultimately, its the number of cold starts that kills the starting cat, causing the light.

Hence the recommendation to move the sensors, which is a total cure.

[Doctor Gollum]

Never bothered on my ex plod, but that was never cold. Or driven particularly gently

[dave the builder]

 

Hi, on my 3.2 I keep getting a warning light o2 bank 2 sensor 1. Where is it on the exhaust? I clear it and it comes back on when crusing at about 40mph.

"bank 2 sensor 1 " is pre cat sensor on bank 2 
not post cat "catalyst efficiency" problems AKA bank 1 or 2 sensor 2   
new O2  sensor ,pre cat ,bank 2 
Is "bank 2 " the 2.4.6 side 

[Doctor Gollum]

Yup 135=Bank1

[dave the builder]

Yup 135=Bank1

so, the O2 sensor on the near side (UK car/ left)  BEFORE the pre cat ( top of downpipe) needs replacing
assuming the OP has read the codes correctly 

not much room to work 

[Doctor Gollum]

Leave the sensor in and fit a new one down stream. If you cba to drive the car rather than pootle it.

[TheBoy]

Ah, I read Bank 1 Sensor 2 for some reason, lol.  Dyslexia rules

What is the actual code, is it could be something else.  Note, Sesnor 1 cannot be moved.

[Migalot]

For what it's worth, i had the same Bank 2 Sensor 1 fault and it took weeks before JamesV6CDX discovered it was actually Sensor 2 that was duff. The engine ECU gets it's Sensor 1 information via Sensor 2, so if 2 is bad, it can incorrectly report 1.

Car ran like a pig until the problem was sorted. Runs beautifully now. 

[TheBoy]

For what it's worth, i had the same Bank 2 Sensor 1 fault and it took weeks before JamesV6CDX discovered it was actually Sensor 2 that was duff. The engine ECU gets it's Sensor 1 information via Sensor 2, so if 2 is bad, it can incorrectly report 1.

Car ran like a pig until the problem was sorted. Runs beautifully now.

I'd say it was more likely that their connectors had been crossed.   S2 has no impact on engine metrics, its just an emissions test.  S1 controls the fuelling.

[deviator]

I used to use lambda spacers on the 2.6 Vectra. They took the tip out of the flow and stopped the codes.