Robert Ottavio

Code P0158 came up, 02 sensor too high circuit Bank 2 Sensor 2.

I replaced the 02 sensor.

Now code P0161 comes up. Heater circuit shortened on opened. It’s referring to the same sensor I just replaced, Bank 2 sensor 2.

Any idea how to fix this? The jeep runs bad in idle and I I dove it for awhile, turn it off and back on it doesn’t want to start. I’m assuming this is why?

thanks

Noah911

1. Locate the oxygen sensor and disconnect it from its harness connector.
   
2. Locate the DK GRN/ORG (or VIO/WHT) wire of the engine wiring harness oxygen sensor connector.
3. With your multimeter in Volts DC mode, probe the DK GRN/ORG wire with the red multimeter test lead.
   
   Ground the black multimeter test lead directly on the battery's negative terminal.
   
4. With the Key On Engine Off (KOEO), the DK GRN/ORG (or VIO/WHT) wire should have 10 to 12 Volts DC.

Let's take a look at your test results



(edited to add):
TESTING PROCEDURE FOR A WJ GRAND CHEROKEE. THE WIRE COLORS MAY BE A LITTLE DIFFERENT IS ALL.

Dave51

Please add the year to your sig so people don't have to go back and hunt cause it's often important (OK I found yours, 2001).

For 20 years, the S2 sensor did nothing except guess if the cat was bad, so it essentially had no purpose (with all due respect to the tree huggers)

Well, then they started making quad cats and guess what?

Anyway the harness is probably burnt somewhere, check the entire length, but especially where it's near the exhaust.

Dave51

Or whenever they added downstream O2 sensors.

Robert Ottavio

Unplugged my B2S2 and this looks like the problem and why it’s reading code P0161. I was able to use needle nose pliers and straightened it out and plug it back into the O2 sensor correctly. I’m hoping that fixes it and it wasn’t permanently damaged.

Dave51

Thanks for the follow-up!

Robert Ottavio

I erased the code just now so I’ll know in about a day or so if that fixed it or not.

Robert Ottavio

Code is still there 🤦🏻‍♂️

Andrew6145

That is completely wrong. Up to '95 model year, vehicles had an o2 sensor before the cat. It was less common to have a cat per head too so usually only one, higher end vehicles with cat per head had 2. These monitor the oxygen in the exhaust to allow the ECU to maintain proper air/fuel ratio. '96 and later, for pollution control, is when they added the down steam I2 sensors. The only thing they do is monitor the performance of the cat. If you have an upstream O2 sensor malfunction, it will affect fuel economy and engine performance. If it is down steam, the check engine light may be on, but vehicle performance/ economy won't be affected.

Dave51

Don't tell me kid, tell Daimler Chrysler. They're the people that say

Ryan Durty

Andrew6145

So I'm having the same issue, and the only code reading is P0161. although My engine isn't running bad, and gas hasn't seemed to be affected, I've noticed that my engine temp is running slightly lower then usual, it's getting colder now that Winters beginning, and it seems that it's making my engine temp to run slightly colder, which is causing my inside heat to not run or blow as warm. Could this be related?