Which Oxygen sensors to use on 1998 Cherokee with 4.0 engine

[Ray1942]

Can anyone tell me which oxygen sensors I should be using on my jeep..?? I've got NTK 23151 upstream before the cat. and NTK 23099 down stream after the cat. ... both new, but still can't pass the smog emission, because they don't show up in the monitor as registering...
I've visited several sites and have been told to use the same Bosch #13122 both up stream and down stream.... but other sites say I'M supposed to run two different sensors..?"? sites say it doesn't matter, that it all pertains to what length of electrical pigtail in installed on the sensors, one is 12 inch and one is 16 inch..!!! ANYONE WITH THIS KNOWLEDGE PLEASE GIVE ME THE CORRECT ANSWER:bomb: This has been going on now for over 2 years and still can't get my Jeep registered because it won't pass the smog...!!!!

 

[JPNinPA]

For any Jeep sensor use only OEM. The NTK is the correct choice. Verify you do not have a intake leak or a exhaust leak before the CAT(s). Also check your wiring to the O2 sensors. It is possible they are dry cracked or brittle.

Do not get anything on the sensor. Use conductive anti-seize on the threads. You may have to drive a few trips totaling 500 mi to get old data overwritten. Otherwise you might still fail due to old data.


JPNinPA
Using Jeepz.com app

 

[Ray1942]

For any Jeep sensor use only OEM. The NTK is the correct choice. Verify you do not have a intake leak or a exhaust leak before the CAT(s). Also check your wiring to the O2 sensors. It is possible they are dry cracked or brittle.

Do not get anything on the sensor. Use conductive anti-seize on the threads. You may have to drive a few trips totaling 500 mi to get old data overwritten. Otherwise you might still fail due to old data.


JPNinPA
Using Jeepz.com app

Thanks for the info. I will try your ideas for sure, and i'll let ya know if they work for me..!!!

 

[Ray1942]

Hey..JPNinPA I tried your advise, didn't help me any.. not your fault... I'm now trying to see if the sensor has power to it, I've disconnected the pigtail to it and have turned the ignition to the on position, and tested with my tester, on all 4 prongs of the power cord... but it doesn't show any power going to it from the vehicle... Does the engine need to be started and running to get power to the sensor ???? Oh and the fuse was checked and was good... now just pulled the fuse and checked out the slot, no power to the slot... :???:

 

[JPNinPA]

Is your check engine light on? If so have you gotten the codes? What are they?
Here is the color code for a 98

Engine Harness

Sensor Signal - Tan/Black
Signal Ground - Brown/Yellow
Heater Power - Dark Green/White
Heater Ground - Black


Sensor Wires

Sensor Signal - Black
Signal Ground - Gray
Heater - Both Whites. There is no polarity.

To read the voltages you need the correct scan tool.
You should see "OPEN" when you first start the engine and when the PCM time out it should announce "CLOSED"
When the PCM is in Open Loop the Oxygen Sensors are ignored by the PCM and will not show any activity on your scanner, except that the voltage readings should be 1.00 volts. When the PCM goes in to Closed Loop the Oxygen Sensors are brought in to play and you should be able to see O2S1 voltages toggle back and forth about very 2 seconds above and below the rich/lean crossover - approximately .045 volts (.001-.900). You may see the O2S1 voltages toggle.

O2S 2 voltages will be a little bit slower but should never show the same exact voltage of the O2S1, or stay near .900 .
A 1v constant reading is a dead O2

Regards,
JPNinPA

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