HELP P0152 and P1152

[mrau92me]

My mountie was running rough and the Svc Engine Soon light would flash but not all the time. Flashing SES means CATs could become damaged (since raw fuel can damage them) if continue to drive it. Scan indicated P0305 and P0306 (cyl 5 & 6 misfire) codes which could cause the flashing CEL if fuel not being burned.

I had just installed new NGK plugs and MC wires 2 months ago, so I did a spark test on the ignition coil and some plug wires and was getting no spark at all out of the coil's #5 port, except upon startup. So, I disconnected battery & changed the ign coil which had been there for all 169k miles. I ran the spark test again and got spark to the #5 plug boot, so it seemed golden. I drove it around my neighborhood a little and ran perfectly the first time. Drove it around block a 2nd time, seemed a little rough but I thought it was just relearning settings after battery disconnect. 3rd time, SES came on and ran rough & lacked power, so took it & got a free scan at adv auto. No misfires indicated this time but got P0152 (02 Sensor Circuit High Voltage-Bank 2 Sensor 1) and P1152 (Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Rich - Bank No. 2). On the way home, however, it then ran fine. BTW, #5 & #6 cyl are on Bank 2. Is there fuel from the misfire condition in the exh manifold that has not cleared out yet that caused the O2 sensor to generate these new codes? Are the O2 sensors fouled from unburned fuel? Any ideas would be greatly appreciated. Thanks.

 

[mrau92me]

Drove it a few minutes ago. From cold start, it idled very rough, thought it was going to quit, but gave it some gas and it seem to smooth out the more it ran. Then, it ran like a champ. Let it sit about an hour and half, and then got the same result. BTW, the O2 sensors are the original ones.

 

[MrBean]

sounds like a bad O2 sensor to me

 

[mrau92me]

sounds like a bad O2 sensor to me

I wasn't sure since the O2 sensor was basically reporting a rich condition which is what happens when plugs aren't firing and that was what was happening due to the bad ignition coil. I decided to wait it out. I read on anothe site that if you run some Gumout with Regane through the gas tank after having misfire condition, it will clean the O2 sensor that gets gummed up due to the unburned fuel. I haven't even put any in it yet, and the SES light is not even on anymore (altho it isn't exactly running right at cold start yet). I put in some BP gas (with Invigorate in it) right after replacing the coil, so perhaps that has already cleaned it up some.

Thanks.

 

[J_Train]

you do not want to try to clean the o2 if they are bad they are bad. swap the o2 sensors and see if the codes come back but for the other bank of cylinders.

 

[MrBean]

somebody had this issue before, i dont have the link to the thread on this running rough issue...but his issue was running running rough at start up and coming to a stop...no codes...fuel pressure was fine...this person took it to a shop and the shop hook up their scanner and went for a drive and found out that the O2 sensor was inop..it stuck on lean...so ecu kept adding fuel...that is why it was rough...im guessing your X is over 150k...i would replace it if i were u...good luck!

 

[mrau92me]

The ECU cleared the codes on its own (meaning it's not detecting a rich condition from the o2 sensors anymore). Swapping the O2 sensors is a good idea. I'll do that if the codes come back. I'm going to run the Gumout through a couple of half tanks and see if that clears it all up. If it continues to run rough at start-up, my Bank 2 sensor may be stuck on a "rich" condition as MrBean suggests and I'll change the sensor out. Thanks for the great input!