2005 Ford Taurus, 6cyl, 3.0L, OHV, 90K miles. CEL came on and code read was P2272 with info “O2 Bank2 sensor2 signal stuck lean”. Should I assume that I need to replace one of the O2 sensors and if so, which one ?? Not sure, but I think this car has four O2 sensors ??
The car does have 4 O2 sensors. There are 2 for each “bank” of cylinders. A bank is just a row of cylinders on one side of the engine.
Bank 1 is the row of cylinders that has cylinder 1 on it. You can determine this from checking out the firing order of the plugs. Thus bank 2 will be the other bank.
Sensor 2 will be the sensor after the catalytic converter (a.k.a. “downstream”). Sensor 1 would be the one before the catalytic converter. Lucky you - sensor 2 has you crawling down underneath the car.
This code might mean that you need to replace the sensor. The first thing to do is just inspect its wiring & wiring harness. If you have a multimeter & can actually check the power supply, then all the better. Someone with a scantool could also check out the actual sensor operation. Its likely that all the code really means is that the voltage reading coming from that sensor is off. It could be off because the sensor has a problem. It could be off because there’s actually an issue that is leaving the exhaust too lean. That, however, would be most likely to show up on upstream sensors.
Thanks for the info, cigroller (I wasn’t sure which O2 sensor it would have been). I’m actually happy that it’s the downstream sensor because I have access to a car lift and easy access to that area. I once had to replace an upstream sensor on an F150 which was a pain - no access underneath or under the hood. Thanks again!
I Like Doing The Cheapest, Easiest Things, First.
I’d Check The O-ring On The IMT (Intake Manifold Tuning) Valve, First.
It Was A Known Problem On Some Of These Cars.
Ford’s got a TSB (Technical Service Bulletin) that applies only to 2005 Taurus/2005 Sable vehicles equipped with a 3.0L 2V, and 2003-2005 Lincoln LS vehicles equipped with a 3.0L 4-V engine.
The bulletin was written to help Ford technicians and outlines procedures to check the valve when the CEL is on and/or lean codes are set or if one can hear a vacuum leak noise.
Remove the valve and inspect the o-ring. If it’s damaged or flat then replace the o-ring. Put some clean oil on the new o-ring (87072-S91) before installing it.
If the o-ring is OK or doesn’t solve the problem then further diagnosis is required.
Will take a look at this - thanks, CSA.
Please Let Us Know.
Assuming it is the oxygen sensor:
keep in mind getting the oxygen sensors out clean can be an issue if you are in a state where they salt the roads x 10 that first statement. I coulnd get the ones out of me ford focus catalytic converter at all. I coulndt get the ones out of the F-150 truck without losing the head of the sensor in the manifold.
Just keep in mind - it may be worth your time to but the manifold and the sensors for that side - that is if the TSB falls through.