Jeep Wrangler 2005 Oxygen Sensor heater monitor not completing for smog

code p 0320 refers to crankshaft position(CKP) sensor /engine speed ( RPM) sensor ---circuit malfunction===causes --wiring---CKP/RPM sensor---ECM
code p 04310 refers to warm up catalytic converter, bank 2--efficiency below threshold===causes ---cat converter---wiring---HO2S 2
As it is not passing the smog test I would be replacing the HO2S sensor ( manifold or before the cat on bank 2 of the engine ) or more likely a failed cat converter
you may have had the P 0320 code for a long time and have not noticed a drop in performance but as cat converters have a lot to do with smog control , that is the area I would advise checking first

99 or 98/, you showed both in the the blue box
great the 4.0L engine displacement, nobody ever post engine.
congrats
The CEL glowing is and OBD2 feature, it tells you things that
are about to fail and things that have/
The ECU can even mimic bad sensors. (poorly) and fool you in to thinking car runs good, this magic cuts smog big time)
P0 is a federal code (USA) and is a standard.

this car has 2 oxygen sensor. one front and 1 rear.
the rear is failing. (bad sensor, road damaged or wires cut or melted)
it only is used to detected a bad Catalyst converter.
it monitors the CAT. it will not effect engine fueling rates.
The front sensor is the imporantant one.
most folks ignore it , unless getting smogged,


the B1S2 oxy sensor is sending an illegal output.
way over 1v.
caused by a cut wire to same. (it floats high)
or inside the sensor the heater B+ is shorted to the sensor output..
bad sensor or cut wires.

What does that mean? Basically this means that the oxygen sensor downstream of the catalytic converter on bank 2 is detecting that the converter is not working as efficiently as it should be (according to specs). It is part of the vehicle emissions system. Symptoms You will likely not notice any drivability problems, although there may be symptoms such as a rough/hard idle when cold. Causes A code P0431 may mean that one or more of the following has happened: The catalytic converter is no longer functioning properly An oxygen sensor is not reading (functioning) properly There is an exhaust leak Possible Solutions Inspect for exhaust leaks. Next step is to measure the voltage at the oxygen sensor on Bank 2. In fact, it would be a good idea to test each oxygen O2 sensor while you're at it. One thing to note is that many vehicle manufacturers offer a longer warranty on emissions-related parts. So if you have a newer car but it's out of it's bumper-to-bumper warranty, there still may be warranty on this type of problem. Many manufacturers give a five year, unlimited mileage warranty on these items. It's worth checking into.

Read more at: http://www.obd-codes.com/p0431
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Sounds like the heater in one of the O2 sensors is not working. But you would need to know which sensor to troubleshoot it.

bank 2 is passenger side depends on what the rest of the code says, should say sensor ? bank 2

This will be the upstream sensor (before the Cat converter) for cylinders 4,5,6. These are the back 3 cylinders.. Hope this helps.

Converter is not working as efficiently in Bank 1 and Bank 2 (two codes)...

P0421 - Warm Up Catalyst Efficiency Below Threshold (Bank 1)
Basically this means that the oxygen sensor downstream of the catalytic converter on bank 1 is detecting that the converter is not working as efficiently as it should be (according to specs). It is part of the vehicle emissions system.

Symptoms: You will likely not notice any drivability problems, although there may be symptoms. The code may be more likely to occur after the engine has had numerous cold starts in the past 1-2 days.

Causes: A code P0421 may mean that one or more of the following has happened:
The catalytic converter is no longer functioning properly
An oxygen sensor is not reading (functioning) properly
A sparkplug is fouled up

Possible Solutions:
Measure the voltage at the oxygen sensor on Bank 1 (the rear sensor, or the sensor after the converter). In fact, it would be a good idea to test each oxygen O2 sensor while you're at it.

One thing to note is that many vehicle manufacturers offer a longer warranty on emissions-related parts. So if you have a newer car but it's out of it's bumper-to-bumper warranty, there still may be warranty on this type of problem. Many manufacturers give a five year, unlimited mileage warranty on these items. It's worth checking into.

P0431 - Warm Up Catalyst Efficiency Below Threshold (Bank 2)
Basically this means that the oxygen sensor downstream of the catalytic converter on bank 2 is detecting that the converter is not working as efficiently as it should be (according to specs). It is part of the vehicle emissions system.

Symptoms: You will likely not notice any drivability problems, although there may be symptoms such as a rough/hard idle when cold.

Causes: A code P0431 may mean that one or more of the following has happened:
The catalytic converter is no longer functioning properly
An oxygen sensor is not reading (functioning) properly
There is an exhaust leak

Possible Solutions:
Inspect for exhaust leaks. Next step is to measure the voltage at the oxygen sensor on Bank 2. In fact, it would be a good idea to test each oxygen O2 sensor while you're at it.

One thing to note is that many vehicle manufacturers offer a longer warranty on emissions-related parts. So if you have a newer car but it's out of it's bumper-to-bumper warranty, there still may be warranty on this type of problem. Many manufacturers give a five year, unlimited mileage warranty on these items. It's worth checking into.


Hope this helps.

A code P0431 may mean that one or more of the following has happened:
* The catalytic converter is no longer functioning properly
* An oxygen sensor is not reading (functioning) properly
* There is an exhaust leak

Possible Solutions:
* Inspect for exhaust leaks. Next step is to measure the voltage at the oxygen sensor on Bank 2. In fact, it would be a good idea to test each oxygen O2 sensor while you're at it.
* One thing to note is that many vehicle manufacturers offer a longer warranty on emissions-related parts. So if you have a newer car but it's out of it's bumper-to-bumper warranty, there still may be warranty on this type of problem. Many manufacturers give a five year, unlimited mileage warranty on these items. It's worth checking into.

Keep us updated and remember to rate thsi answer.

The jeep has air injection and this is part of the air pump. The cat should have two ports.. These tubes should have check valves to prevent backfire.Usually their routed up on both sides of motor and attached at the air cleaner abouts

342 is camshaft position sensor and 431 is your catalytic converter may be getting weak. If this was my car I would do the 342 code and see if the other code for the cat comes back. Tell the shop fix the camshaft sensor. If the sensor is bad your car can still run but its possible you could set a cat code because
of it but on the other hand you cannot set a camshaft code because of a bad cat.

I am a smog tech in California