What does the P0158 O2 circuit high voltage code mean for a Jeep?

Hi, I looked up the code (P0158) and found some helpful info. However, I’m not totally sure what the “bank 2 sensor 2” refers to. I know it means the second sensor on the car, but I would appreciate it if someone could tell me where exactly this faulty sensor is located.

My girlfriend just told me about her check engine light after it’s been on for a whole month.

5 Likes

The sensor is on the passenger side after the catalytic converter. There are 4 sensors total—2 on each side, with one before and one after each catalytic converter. As far as I know, the one after the catalytic converter won’t affect fuel economy. You could try resetting the code first to see if it comes back on.

1 Like

I asked my girlfriend to have the guy at Checker clear the code, but since I wasn’t there when they scanned the Jeep, I’m not sure if he actually did it. Is there a way to reset the codes myself? I’m sure I could find the answer if I searched. :laugh:

So, since this is on the passenger side after the catalytic converter, does this Jeep have a header cat, or just the standard one before the muffler?

I have to disagree about it not affecting fuel mileage. The same sensor went bad in my Jeep, and 60 miles into a road trip, I used up half a tank of gas. I pulled over, disconnected the battery to reset the code, filled up, and after that, I got 200 miles on just half a tank with no warning light. That’s crazy!

The original poster (OP) was talking about an “after the catalytic converter” O2 sensor, and that’s what I was replying to. Those sensors just measure things like exhaust gas temperature and shouldn’t affect your gas mileage.

But if it was one of the sensors “before the catalytic converter,” then it would affect the engine’s open-loop/cold-loop operation, which could impact gas mileage.

So, what was your error code, and which O2 sensor are you having trouble with?

From what I found, it does affect fuel consumption because it measures the amount of oxygen in the exhaust and sends a signal to the computer, which adjusts the fuel. I’m not a mechanic, lol, but I’m dealing with the same codes on my 2003 Jeep Liberty 3.7.

How many O2 sensors does a 2004 Jeep Liberty have? My check engine light came on, and the code was P0158. I changed 3 O2 sensors, but the check engine light is still on. I disconnected the battery, and the light came back on after an hour. I had it checked again, and the P0158 code came up saying O2 sensor 2 bank again. Can someone please help?

There are 4 O2 sensors. Bank 2 sensor #2 is on the passenger side (USA) and located after the catalytic converter. It’s best to use Mopar or NGK/NTK sensors because Jeeps don’t work well with Bosch sensors.

You don’t need a code scanner to check for codes. To see if they are still there, just turn the ignition key on and off three times (without starting the engine). When you turn the key to “on” the third time, leave it on, and any codes will show up on the odometer display.