I recently had an p0138 on my obdII readout on my 2004 jeep liberty?

Question

I'm woundering if the code gives you the location of the malfunctioning o2 sensor. or lets you know which one is malfunctioning. I also need advice on how much the repair would cost and if it is something I can do myself. thanks

To add a few things. WOuld a mechanic need to go on a fishing expedition in my car to find the one that is malfunctioning. or as he says it will be the same price if i replace all 4.

and bfh how about more details so i tell this show owner i took it to that he is full of crap. andI'm in ny.

Answer 1

P0138 02 Sensor Circuit High Voltage (Bank I Sensor 2)

Ok so that is driver side of a 6-cylinder Liberty, 2nd sensor back from the motor. On a 4-cylinder Liberty that would just be the 2nd sensor back from the motor.

High voltage actually means that sensor is reading a rich mixture. A rich mixture is an indication of the motor getting too much gas.

Since its only the 2nd sensor reading this, I'd say odds are pretty high the sensor is bad. Especially since the front O2 sensor closest to the motor isn't seeing the same thing. I looked up pricing here in my area for the sensor you need, and it shouldn't be more than $50.

As far as replacement, it takes a special socket that can be rented at most any autoparts store, and it just unscrews like a spark plug, and has one electrical harness running to it. Being an 04 it should come out with little trouble.

Answer 2

P0138 O2 Sensor Circuit High Voltage (Bank 1 Sensor 2)

Bank one, left. sensor 2, rear, behind the catalytic converter.

Disconnect the wire, unscrew the sensor. You can try cleaning off the carbon and see if it will then behave. If not, screw in a new one and reconnect the wire. Part will run up to $100 depending.

Gets a little more complicated for CA emissions, if you are there, take a look here (actually it gives good information even if you aren't): http://www.4x4xplor.com/O2-sensor.html

Answer 3

I cant believe how many people who claim to be "professionals" are supplying bad answers. The P0138 states specifically that the voltage is high in Sensor 2 ( downstream or at the cat) of bank 1 ( drivers side assuming a six cyl) Although if you have a carb compliant NY vehicle you may have to google up which s bank one as carb compliant four cylinder engines have 4 sensors as well. As someone else noted, since sensor 1 in the same bank is reading good, suspect a bad sensor, AVOID Bosch sensors and go to NTK brand as the Bosch are notorious for not functioning properly in Jeep and Chrysler vehicles.

(added to an old thread for others who suffer this common issue, and to point out the Posers claiming to be professionals who posted in this thread)

Answer 4

It does give you the location of the sensor (there are at least two one before and one after the cat. some have more in other places depending on a variety of factors) Most likely you'll have to ask a dealership for the trouble code definition. I can't find it on the internet. You can replace it on your own with basic hand tools. you might need a oxygen sensor socket but I've only needed it once so far. A sensor ranges from $50 to $120 .

Answer 5

1

Answer 6

i own a repair shop and it usually wont tell you the exact 0-2 sensor it is,but your best bet is to take it and have it checked at a shop,better scanners can narrow it down,the hand help ones most shops have ,wont do this,i have been real lucky with those though its usually the updraft one that goes bad,the cost on replacing these isn't much usually parts and labor together is less then 100 bucks,so have a good shop look it over they can probably go right to the bad sensor,good luck with it.

Answer 7

To answer your question first. P0138 does indeed tell you which sensor is bad. And for everyone who just think they know the answers, add this to your favorites and then you will know the answer:

http://autorepair.about.com/cs/troubleshooting/l/bl_obd_main.htm

Answer 8

1)Yes
2) You haven't given enough info.
3) No

Anyone who tells you different, is WRONG!
Auto zone can't help either...ie you don't nessesarily need an oxygen sensor.
Take it to a repair facility!