02 Liberty Engine probs

[davetheelectrician]

My 02 Liberty (197,000 mi) started missing real bad. engine codes were P0141, P0161, P0202, P0302.
I replaced the #2 injector, plug & coil but it hasn't helped. How can I test the injection wiring & where else could the problem be?

 

[Dave]

My 02 Liberty (197,000 mi) started missing real bad. engine codes were P0141, P0161, P0202, P0302.
I replaced the #2 injector, plug & coil but it hasn't helped. How can I test the injection wiring & where else could the problem be?

Hi Dave. Welcome to the forum.

P0141=HO2S heater performance-bank 1 sensor 2 (drivers side after tha cat sensor)

P0161=HO2S heater performance-bank 2 sensor 2 (pass side after the cat sensor)

P0202= Injector 2 control circut

P0302 Cyl 2 misfire

Seems like you should have corrected the misfire with the replacement of the plug and coil pak.

The first 2 codes might be related to the misfire as the sensors after the cat measure the heat of the exhaust leaving the cat.

You could try double checking the connector to the #2 coil-pak and then reset the codes and see if they come back. I don't know what else to suggest.

Dave

 

[davetheelectrician]

Thanks for the quick reply. I have done some further diagnostics. A compression check shows 180 on all cylinders EXCEPT #2 which shows 0. The zero on 2 was a shock as I was expecting a possible LOW reading...but not THAT low! Could I be dealing with a thrown rocker arm?? I have heard this is a known bug in the 3.7 & 4.7 engines. Is there any other testing I can do before pulling the valve cover?

 

[Dave]

As far as I know you would need to pull the valve cover to check. (but I am not a professional mechanic)

Dave

 

[pejofag]

Hello, I just want to know how to reléase the oil pan after loose all bolts