P0137/P0138 Codes

Hey guys! So I had my Jeep sitting for about a week, and after about 10 minutes of letter it idle to get it up to running temp and clear some frost off the inside of my windshield, I started to drive. Well my CEL came on, yet I didn't notice any performance difference in the Jeep. Nothing significant at least. So I took it to my local parts shop and they let me scan it, so I got two codes.

p0137 Generic Circuit Low Voltage Bank One Sensor Two
p0138 Generic Circuit High Voltage Bank One Sensor Two

I've read some stuff about this being one of the sensors for the driver's side Cat. The Jeep seems to maybe been running with a little less power, a bit sluggish, but nothing too crazy. It's always been slow anyway:icon_lol:

Anyone have any experience with this? Any advice?

Ya I think they are both 02 sensor codes, NTK replacement time...
Others more familiar should chime in shortly as well.

Hello what year is the jeep? How many miles on the clock?

Bert

'06 with 157k. Getting up there, but she's ran reliably so far!

Like LibertyTC said, probably time for a new driver's side post cat sensor. I would say check the connector and wires leading to it first. If all okay I'd try a new NTK or Mopar sensor. Bosch don't work well in these vehicles.

You mentioned that a local parts store let you use thier tool to scan the Jeeps computer........go back to that store and ask them if you can use the scan-tool again......and this time, select the scan-tools "real-time-data" option and look at the Live Data numbers that the B1S2 is displaying. The display should show a fluctuating voltage reading between .001v and 1.0v but realistically, the voltage display should move around between .300v and .600v

If the voltage reading drops below .000v then it is bad......if the voltage raises above 1.001v then it is bad as well.

What you can do is swap the B1S2 sensor with the B2S2 sensor, clear the code, drive the Jeep and when the Check Engine light comes on again......you scan the computer and you should come up with the same codes relating to B2S2, if infact this happens, replace the o2 sensor.......If after you swap o2 sensors and are still getting the same Bank 1 Sensor 2 related codes, well then the prob is with bank 1

Low voltage AND high voltage codes at the same time on the same sensor could also indicate a faulty ECU (ouch.....worse case scenario).

These o2 sensors run off of 5v with a reference signal and a ground signal and a return signal back to the ECU and a reference sinal out to the next sensor.....sounds complicated, but in reality....just 4 wires.......both downstream sensors are interchangeable with each other. Look along the o2 sensor wire harness and see if you spot some burned wires. If wires are burned, you can cut out the burnt section of wire and splice in new wire. The wire is basic electrical stuff. No need for special wire or wire coatings.....just be sure to tie up the wire OFF the hot exhaust pipes.


As a side note......that drivers side cat is $1,300 at a Mopar dealership.....MagnaFlow offers a "direct Fit" replacement for less than $400.....I know this because I just ordered 2 cats.......the MagnaFlows