DIY P0141, P0141 and Heated Oxygen Sensor Replacement
07-28-2014, 10:33 PM
#1
Drifting
Thread Starter
DIY P0141, P0141 and Heated Oxygen Sensor Replacement
I found bits and pieces of information on this problem but nothing all in one post, so here goes:
P0140 is Bank 1 Sensor 2 & P0141 I Bank 1 Sensor 2b. They relate to the heated oxygen sensor after the catalytic converter and do not affect engine performance, but rather let you know that your catalyst may not be functioning.
My car is 2002 Z06 with 40,000 miles driven to work and tracked a few times per year. About 2 years ago the check engine light would come on every once in a while and then go off for maybe a week or two. I used the onboard diagnostics by pressing OPTIONS and then FUEL 4 times which indicated that a P0140H code was set. It seemed to go off after a long highway drive or a few hot laps on track. In fact I got it thru emissions testing two years ago by taking it for testing on the way home from track time event. The car ran fine and exhaust did not smell funny so I ignored it or reset the light every once in a while. I assumed that if the cat was really bad the CEL could not be reset for more than a few ignition cycles.
Lately it has been on virtually all the time and I need it fixed to get thru emissions testing. Also P0141 code was set. I bought a new AC Delco sensor from Gene Culley as I figured it had to be either the sensor or the wiring.
I had access to a drive over oil change pit so I did not have deal with jacking up car.
It is confusing as to which sensor is Bank 1 Sensor 2. Obviously it is the rear HO2S, but which side? The manual shows the plug on the harness to have pins A, B, C & D with wires Tan/White, Purple/White, Black and Brown. Bank 2 is similar but colors are Tan, Purple, Black and Brown. It turns out that the connector for Bank 1 is on the passenger side of the transmission tunnel, but the sensor is on the driver’s side pipe. You can see the striped wires going into the back of the connector pretty easily.
Getting the sensor unscrewed was pretty easy with a large 22 mm open end wrench. The exhaust was hot as the car had been driven for about 15 minutes. I believe the hot pipe is the key to not having problems loosening the oxygen sensor so you should break it loose first. The connector is forward and really close to the exhaust down pipe so you have to be really careful not to get burned. We misted the pipes with water to get rid of some of the heat.
Pull the blue lock pin out of the connector first and then disconnect. Then use a screwdriver to spread the clips that hold the wires under the heat shield. Once you have the wiring hanging you can spin the HO2S out without twisting the wires.
Reassembly is just the reverse. The most time consuming part was trying to get the wires back into the clips under the heat shield.
P0140 is Bank 1 Sensor 2 & P0141 I Bank 1 Sensor 2b. They relate to the heated oxygen sensor after the catalytic converter and do not affect engine performance, but rather let you know that your catalyst may not be functioning.
My car is 2002 Z06 with 40,000 miles driven to work and tracked a few times per year. About 2 years ago the check engine light would come on every once in a while and then go off for maybe a week or two. I used the onboard diagnostics by pressing OPTIONS and then FUEL 4 times which indicated that a P0140H code was set. It seemed to go off after a long highway drive or a few hot laps on track. In fact I got it thru emissions testing two years ago by taking it for testing on the way home from track time event. The car ran fine and exhaust did not smell funny so I ignored it or reset the light every once in a while. I assumed that if the cat was really bad the CEL could not be reset for more than a few ignition cycles.
Lately it has been on virtually all the time and I need it fixed to get thru emissions testing. Also P0141 code was set. I bought a new AC Delco sensor from Gene Culley as I figured it had to be either the sensor or the wiring.
I had access to a drive over oil change pit so I did not have deal with jacking up car.
It is confusing as to which sensor is Bank 1 Sensor 2. Obviously it is the rear HO2S, but which side? The manual shows the plug on the harness to have pins A, B, C & D with wires Tan/White, Purple/White, Black and Brown. Bank 2 is similar but colors are Tan, Purple, Black and Brown. It turns out that the connector for Bank 1 is on the passenger side of the transmission tunnel, but the sensor is on the driver’s side pipe. You can see the striped wires going into the back of the connector pretty easily.
Getting the sensor unscrewed was pretty easy with a large 22 mm open end wrench. The exhaust was hot as the car had been driven for about 15 minutes. I believe the hot pipe is the key to not having problems loosening the oxygen sensor so you should break it loose first. The connector is forward and really close to the exhaust down pipe so you have to be really careful not to get burned. We misted the pipes with water to get rid of some of the heat.
Pull the blue lock pin out of the connector first and then disconnect. Then use a screwdriver to spread the clips that hold the wires under the heat shield. Once you have the wiring hanging you can spin the HO2S out without twisting the wires.
Reassembly is just the reverse. The most time consuming part was trying to get the wires back into the clips under the heat shield.
