Beerbelly

I have a '12 sport, I bought it with 21000km on it. Soon after, it started chugging and acting up, so I took it to a dealership and they said it was bad gas (piss me off).I bought a code reader and it told me I had bad O2 sensor on bank 2, so I chNGED it. Worked fine for a while but every so often, it will start to act up again. I put the code reader back to work yesterday and got this.

P0152 O2 sensor bank2 sensor 1
P0300 random multiple misfire
P0430 cat system efficiency below threshold bank 2

My buddy figures it has something to do with my valves, lifters, etc.
It now has 77000 k on it, it has burned about a litre of oil between oil changes ever since I bought it

Beerbelly

Any Ideas?

rob_engineer

I'm not saying it's related, but it is at least worth looking into the bad head issue that some 2012's had. At one point someone in this forum made an excel file of people's symptoms when the bad head problem affected their jeeps. The warranty on the 2012 for the left side head problem is extended to 150,000 miles.

Mr.T

Best way to diagnose O2 sensors is scanning the voltages and graphing them. The codes indicate a problem, but it takes diagnosis beyond the code to really know what to replace. There's youtube vids and other websites with details, but it might take more than what your existing scanner can do.

Which O2 sensor did you replace, and what brand / part number?

Here's P0152 Possible Causes:
(K43) O2 2/1 SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE
(K902) O2 RETURN UPSTREAM CIRCUIT SHORTED TO BATTERY VOLTAGE
(K43) O2 2/1 SIGNAL CIRCUIT OPEN
(K902) O2 RETURN UPSTREAM CIRCUIT OPEN
O2 SENSOR

And here's P0430 (Bank 2) Possible Causes
EXHAUST LEAK
ENGINE MECHANICAL
AGING O2 SENSOR
CATALYTIC CONVERTER
PCM

gfe jeep

Suggests you replace the Crankshaft Position Sensor

I bought an after market one and it didnt work - buy the MOPAR part if you decide to give that a try.

I had a cracked manifold on the drivers side. If you replace it yourself, be sure to use a MOPAR gasket - after market ones are too thin ( IMO )

I had 4 O2 sensor codes - I tested each one and they were ok - Ohm it to see.
My problem ended up as a BAD PCM. When they was replaced, after all the trouble shooting I did, it solved my problem. Like Mr T said above, I think too much voltage damaged the PCM although it kept giving me codes to think about!

He helped by telling me how to determine if the O2 sensors were bad.

I hope this helps! George

Beerbelly

The thing is also, it'll do the herky jerky dance for a day or two, then be fine for a few months. Is that the cat have a spaz attack? It usually happens at the beginning of a new season, first real cold or first spring rainy season.