Any O2 sensor gurus?

[dbeardslee]

Anybody know if O2 sensors require break-in? I just changed 'em out on my 2000 Cherokee, and I'm getting a P0132 error code (O2 sensor, bank 1 sensor 1), but the mileage improved significantly and it's running great. I've cleared the code twice, and I'm just wondering if the rest of the system needs to get used to the new parts, or if I got a bad sensor. I've only run it 5-10 miles with the new parts. Any input?

[ViperRon]

An O2 sensor is just one part of the system monitoring and adjusting fuel mix. Many other things may adjust out of spec to adjust for the previous bad O2 sensor. Some systems need to follow a procedure to reset the system.

I had a truck that had air sensors on the wheels for tire pressure. One tire low you get error message 2 tires low driving it cut off after 5 minutes and needed special sequence to reset. Same truck had oil change interval error code and had to get dealer to reset it what a pain in the A$$. Of course it all could have been reset if we purchased the ONstar system was the dealers answer

[puskrat]

An O2 sensor is just one part of the system monitoring and adjusting fuel mix. Many other things may adjust out of spec to adjust for the previous bad O2 sensor. Some systems need to follow a procedure to reset the system.

I had a truck that had air sensors on the wheels for tire pressure. One tire low you get error message 2 tires low driving it cut off after 5 minutes and needed special sequence to reset. Same truck had oil change interval error code and had to get dealer to reset it what a pain in the A$$. Of course it all could have been reset if we purchased the ONstar system was the dealers answer

Thank your ambulance chasers for that one

[dbeardslee]

An O2 sensor is just one part of the system monitoring and adjusting fuel mix. Many other things may adjust out of spec to adjust for the previous bad O2 sensor. Some systems need to follow a procedure to reset the system.

I had a truck that had air sensors on the wheels for tire pressure. One tire low you get error message 2 tires low driving it cut off after 5 minutes and needed special sequence to reset. Same truck had oil change interval error code and had to get dealer to reset it what a pain in the A$$. Of course it all could have been reset if we purchased the ONstar system was the dealers answer

I disconnected the battery last night and let it sit overnight that way. A friend told me that would reset the computer. Not sure if I believe it or not, but what the heck - figured it's worth a try. Haven't run it yet today, but we'll see how it acts.

On a related issue, I think I may have found the perfect tool for removing old O2 sensors. First I tried an O2 sensor socket, which seems to have been manufactured with the intention of rounding off anything it came in contact with. So I got in my toolbox and retrieved my little baby pipe wrench (about 7" long) and a 4' piece of pipe I use for a breaker bar. Those old O2 sensors have been in there for 16 years, and that little pipe wrench with a breaker bar broke 'em loose with no tribble a-tall. I'll have to remember that next time I change an O2 sensor.

[dbeardslee]

Well I took a short run to the donut shop, and the light came on. Cleared the codes in the parking lot, and it came on again on the way back. Now I'm starting the think it might not be the correct upstream sensor. Part of the problem is that model year had both California and Federal emissions systems, and it's tough figuring out what part is correct for mine from auto parts store descriptions. I ordered a new sensor that says it's specifically for upstream, bank 1 sensor 1, federal non-california emissions, along with a new MAP sensor. Parts are supposed to be in tomorrow, so we'll see how that turns out.

[soccer4m]

what is the code

Howdy,,,what is the number for the code you got? Look up the code and it details the possible problems. Unfortunately, many folks keep throwing money at changing a lot of sensors and it usually is the catalytic converters that are the problem. With mileage over 80,000 its a bet that worn out cats are the problem not the sensors......just a guess from experience............good luck,,,,,,,,,,,Mike in Sun DIego

[ViperRon]

Catalytic converter, EGR, injectors all can cause issues and the wrong sensor I am not sure depends on if other parts are different with the other emissions system maybe. Some systems have a test you can do with a meter to see if the output of the sensor is correct. An issue I have had before is a harness getting down on a hot pipe and melting insulation shorting out my computer so check the wiring for burns or wear spots.

The O2 sensor in my Dodge Dakota had 200,000 on it and I never had replaced it or gotten an error. When I wrenched it out there was nothing there it had all burnt away just a plugged hole. Mileage got better when the new one was put in.

[dbeardslee]

Howdy,,,what is the number for the code you got? Look up the code and it details the possible problems. Unfortunately, many folks keep throwing money at changing a lot of sensors and it usually is the catalytic converters that are the problem. With mileage over 80,000 its a bet that worn out cats are the problem not the sensors......just a guess from experience............good luck,,,,,,,,,,,Mike in Sun DIego

Code is in the OP, and it points directly to the O2 sensor - bank 1 sensor 1.

Wiring all looks good, and my fuel mileage is up about 2.5 mpg with the new sensors - about the same as when the vehicle was brand new. And I bought it new, so there's no concerns about what a PO may have done - Chrysler Corp was the PO. ...On second thought, maybe I should be concerned.

At any rate, I cancelled the code a third time, and so far the check engine light hasn't come back on - but I only drove it up to the corner store and back. If it comes back on again I'm going to replace the upstream sensor with a different manufacturer's part and see what happens.

[MPittma100]

Sensor

Code is in the OP, and it points directly to the O2 sensor - bank 1 sensor 1.

Wiring all looks good, and my fuel mileage is up about 2.5 mpg with the new sensors - about the same as when the vehicle was brand new. And I bought it new, so there's no concerns about what a PO may have done - Chrysler Corp was the PO. ...On second thought, maybe I should be concerned.

At any rate, I cancelled the code a third time, and so far the check engine light hasn't come back on - but I only drove it up to the corner store and back. If it comes back on again I'm going to replace the upstream sensor with a different manufacturer's part and see what happens.

If it is a V8, you could switch the sensors out - bank 1, sensor 1 with bank 2, sensor 1) and see if the error code follows the sensor.

Part of the computer self test includes a readiness test. This takes quite a few miles to complete under various driving conditions. All error codes have to stay off for it to complete that test. This test also has to be completed to pass emission inspection in many states.

[dbeardslee]

If it is a V8, you could switch the sensors out - bank 1, sensor 1 with bank 2, sensor 1) and see if the error code follows the sensor.

Part of the computer self test includes a readiness test. This takes quite a few miles to complete under various driving conditions. All error codes have to stay off for it to complete that test. This test also has to be completed to pass emission inspection in many states.

It's a Cherokee, not a Grand Cherokee, so it's got the I6 motor. With the federal emissions (non-ca) it's only got two sensors - an upstream and a downstream. Currently I've got a Bosch 13399 in the upstream position, and according to the parts store description it should work in any upstream position - but I'm starting to think it's only for 4-sensor type systems. I've got an NTK 23506 on order at O'Reilly, and it says it specifically fits upstream bank one, sensor 1, with federal emissions.

But before I do anything I'll take a longer drive with it this evening and see if the light comes back on. If it does I'll change out the upstream sensor tomorrow.

[Old Red]

A PO 132 code is a rich fuel mixture code. I would check the air filter or anything that will make it run rich.

[DiverRay]

How many miles on it? If you have over 100K, think about replacing the injectors. When they get old, they LEAK, and you are running rich. Most of the "good" injectors go for about 150K MAX. You should be able to get rebuilt injectors for about $40-$50 Each, if they are a common type.

[bikerphil]

Doug, some vehicle computers do not like the Bosch sensors, for example an 06 Trailblazer I worked on would keep throwing codes with the Bosch, but was fine with the OEM Delco. If you can't get it figured out, I would try an OEM Mopar sensor.

[dbeardslee]

So I took it for a longer drive last night, and got the check engine light again. So I parked it, picked up the new sensor this a.m., and I just put the car up on ramps to make the swap. When I took a look at the installed sensor I was surprised to see all four wires broken and dangling. That sensor is pretty close to a drive shaft with a zerk fitting on the end. Looks like the zerk fitting got a hold of the wires and broke 'em. I thought I had 'em up out of the way, but evidently not. I'll make doggone sure they're out of the way this time. At any rate, I'm pretty sure the sensor is the problem.

[dbeardslee]

Got the NTK sensor installed, and took a 17 mile test drive - no check engine light, and combined highway/city mileage was 20.1 mpg. The EPA numbers are 16 city and 21 highway, so that's pretty good mileage for this vehicle.

I still think that Bosch 13399 was the wrong sensor for this vehicle. Reason I say that is when I first installed it I got the light, but the mileage was up about where it is now. When I test drove it last night I was only getting about 15 mpg no matter how I babied it, but I'm sure that was with the broken wires. So I think they broke somewhere during the process, but I don't think they've been broken the whole time.

Which brings me to the replacement part - an NTK O2 sensor. It's oem spec, and it included the little push-pin mounting plate thing that the Bosch did not include. The wire is a bit shorter, it mounts much more solidly, and I don't think that wire is going to be able to reach the drive shaft again. And it's made in Japan.

When I was a kid "Made in Japan" had pretty much the same connotation as "Made in China" has today. Funny how times change. Lesson learned - next time I have to replace an O2 sensor, I'll be looking at NTK first.