Any O2 sensor gurus?

[dbeardslee]

Part of the problem with the factory injectors on the 4.0L jeep motor is that they only have one relatively large orifice in the tip of the injector. Jeepers claim they spray a stream of gas into the piston wall, which is not the greatest atomization. The new injectors have four smaller orifices for improved atomization. Sounded reasonable to me, and it does seem to work.

Another thing that's different - with the new injectors I can hear the tic-tic-tic as the injectors spray. Somewhere along the line the tic-tic-tic sound went away on the old injectors. Don't know if that's a good or bad thing, but judging from the results with the new injectors I'm thinkin' that was a bad lack-of-sound.

Course with 395K on the Honda, you might want to consider keeping the injectors and replacing the car around them.

[Jerry]

Hmmmm....Honda is coming up on 395,000 miles and is still running the OEM injectors...maybe I need to change them out...

[dbeardslee]

The new injectors came in today, and installation was a snap. After the past couple weeks of working under a 16 year old vehicle it sure was nice to work up top for a change. I didn't have a bunch of crap falling in my face, and I barely even got my hands dirty. Turns out the simple things in life really are the best.

So after checking for leaks and resetting the computer, I took her for a five mile test drive. I took it pretty easy just to see what the fuel mileage was going to look like, and when I got home I was pleasantly surprised to see that I averaged 19 mpg - and that was city driving. Two weeks ago the best I could have hoped for was about 15.5 mpg, so I was pretty happy with 19. It's way too early to tell what the "real" number is going to be, but I'm cautiously optimistic.

I didn't check it for throttle response, but I did notice the motor seems to idle more smoothly than before, so again, I'm cautiously optimistic.

Bottom line? This looks like it was a good upgrade, definitely needed, and so easy you could probably train a monkey to do it. Good call, Ray!

[dbeardslee]

All it takes is one time for a job like this to pay for a reader. Ford dealership wanted $120.00 just to look at the truck and I didn't even check with the Honda dealer. My unit is pretty basic and does not read transmission codes as many of the newer readers do. Also, it just returns the code and not an explanation; you have to look up the code meaning on-line. Still, I would recommend getting a reader first if you get a Check Engine light since you may be able to do the repair yourself and save some money doing so. Keep in mind, though, that some manufacturers use proprietary codes for some failures that generic readers may not interpret. In my case the $20.00 spent for the reader has saved me probably $200.00 or more by allowing me to fix these problems myself instead of taking my vehicles to a shop.

I agree. I've got an Innova 3100 that will read engine, transmission, and enhanced codes. It'll tell you exactly what was going on with the motor when the codes popped up, too - engine rpm, mph, etc., etc. It also included software that allows you to plug it into a computer to get even more diagnostic info. You can usually go to an auto parts store, and they'll scan your codes for free. Unfortunately the parts store won't fit in my tool box, and it's much more convenient to have my own scanner.

And I'll pass along a little tip on scanners - an East German AK47 magazine pouch works great as a carrying/storage case. The pouch is divided into four internal compartments - the scanner fits in one, cables in another, documentation in the third, and odds & ends go in the fourth. Heck, in a pinch you can even put AK mags in it. And you can find them all day long for three or four dollars....

[Jerry]

Had two run-ins with O2 sensors, one on my 2005 Ford F-150 and the other on my 2001 Honda Accord ES.

Problem on the Ford sensor was similar to your broken wires; the connector plug had come loose, just enough to disconnect the sensor. I removed the plug, shot some DeOxit cleaner into it, pushed it back up into the sensor (passenger side, a real pain) and made sure it "clicked" into place. Cleared the Check Engine light with my $20.00 Autel reader and have had no problems since.

Honda was a different story; Check Engine light would come on after long downhill coasts. Autel reader returned a code that indicated it could be either the manifold (4-cylinder engine) or the downstream catalytic converter sensor. I gambled it was the exhaust manifold sensor and replaced it with a recommended Bosch unit. Cleared the code, no more check engine light when driving the same route.

Got lucky in removing the old sensor; an SAE 7/8 closed-end wrench was all it took to remove it after removing 3 each 10mm bolts that attached a cover over the manifold. New unit went in, plug connectors fit perfectly, was about a 20 minute job all told.

Bosch unit was a bit different design than the Honda OEM; tip was different and just slightly longer. Have put around 10K miles on the Honda (and about the same on the F-150) since working on the O2 sensors and have had no problems since.

All it takes is one time for a job like this to pay for a reader. Ford dealership wanted $120.00 just to look at the truck and I didn't even check with the Honda dealer. My unit is pretty basic and does not read transmission codes as many of the newer readers do. Also, it just returns the code and not an explanation; you have to look up the code meaning on-line. Still, I would recommend getting a reader first if you get a Check Engine light since you may be able to do the repair yourself and save some money doing so. Keep in mind, though, that some manufacturers use proprietary codes for some failures that generic readers may not interpret. In my case the $20.00 spent for the reader has saved me probably $200.00 or more by allowing me to fix these problems myself instead of taking my vehicles to a shop.

[dbeardslee]

Ray is right. Some recommend replacement at 60K miles. Everyone else waits until one of them fails and turns the check engine light on. Then, they only replace that one? You should definitely see better performance and fuel economy. I have experience with that same engine (Wrangler). It needs all the help it can get when talking fuel mileage. It is a tough engine. Chrysler has been using it for a long time. Even back before fuel injection in the carburetor days. Easily go over 200K and keep on keeping on.

I love that big straight six. It's a truck motor if there ever was one. Mine is a Limited, so it's got all the goodies, and I've kept up the maintenance so they all still work. Plus it came with a leather interior, and that's held up real well.

Last year I completely replaced the A/C, along with a new heater core, all new U-Joints (seven of those suckers), and all new steering components. I replaced the front bearing units and brakes last week, and the rear's are next on the list after the fuel injectors.

I'm not sure I'd have been so meticulous with my maintenance if it wasn't for that I6 motor. But I new it was a long-lived sob, so it made sense to keep the maintenance up on the rest of the vehicle. My dad always said "cars don't wear out, you just get tired of fixing them." I haven't gotten tired of fixing this one yet.

[MPittma100]

The original problem seems to be solved, but you got me thinking - always a dangerous thing. The Jeep's got 110,000 miles on it, and after doing some reading up on the stock injectors I decided to upgrade them from single orifice injectors to four orifice units. I found a set of six remanufactured Bosch 4-hole injectors for $137.90, shipped to my door. They're supposed to atomize the fuel better for better economy and throttle response. We'll see. If they don't work, I'm blaming Ray.

Ray is right. Some recommend replacement at 60K miles. Everyone else waits until one of them fails and turns the check engine light on. Then, they only replace that one? You should definitely see better performance and fuel economy. I have experience with that same engine (Wrangler). It needs all the help it can get when talking fuel mileage. It is a tough engine. Chrysler has been using it for a long time. Even back before fuel injection in the carburetor days. Easily go over 200K and keep on keeping on.

[dbeardslee]

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.

The original problem seems to be solved, but you got me thinking - always a dangerous thing. The Jeep's got 110,000 miles on it, and after doing some reading up on the stock injectors I decided to upgrade them from single orifice injectors to four orifice units. I found a set of six remanufactured Bosch 4-hole injectors for $137.90, shipped to my door. They're supposed to atomize the fuel better for better economy and throttle response. We'll see. If they don't work, I'm blaming Ray.

[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.

[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.

[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.

[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.

[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.

[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.

[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.