Service Codes Rough Running/Idling

[mmellott2010]

Started vehicle one morning and it was running rough, service lite came on. Codes are;
1) P0136 bank 1 sensor 2
2) P0156 bank 2 sensor 2
3) P1131 fuel/air mixture
4) P1151
5) P0171 lean
I ran the vehicle for 3 days before I had it checked. If the O2 sensors are bad they would trigger the other ones. Should I replace the (2) rear O2 sensors?????

 

[ssbroly]

How many miles and have you checked for vacuum leaks?

 

[KWT2000]

well the first two codes mean you need at least two of the 02 sensors replaced do that first then go from there

 

[mmellott2010]

No I haven't checked for leaks yet. I parked it for a few days and as soon as I started it up again it started running rough.

 

[ssbroly]

Does it get better at all as the engine gets to normal operating temperature?

 

[mmellott2010]

Thanks, I just bought this vehicle. It's a 1999 Expedition XLT. 120,030 miles Loaded. I paid $2,700.00. It ran fine for like 2 days, I parked it for about 2 days and started one morning and it started to run rough.

 

[mmellott2010]

Thanks, I just bought this vehicle. It's a 1999 Expedition XLT. 120,030 miles Loaded. I paid $2,700.00. It ran fine for like 2 days, I parked it for about 2 days and started one morning and it started to run rough.

No I haven't look for leaks yet.

 

[mmellott2010]

Does it get better at all as the engine gets to normal operating temperature?

Just a little

 

[ssbroly]

Check the o2 sensors, but also, since it gets a little better, I'm thinking a vacuum leak, too. Check the hose for the pcv valve, if that's good, search toward the rear of the block for another leak. It sounds REAL similar to a problem I had. Without the o2 sensors.

 

[mmellott2010]

Ok I will check it tomorrow

 

[mmellott2010]

Hey guys, Thanks alot the idle and rough running and the service codes were caused by a vaccum leak. the line that comes from the back of the engine and goes to the PVC valve. It was a hard plastic line. I guess it broke before I bought the vehicle and they fixed it with a piece of rubber hose. The rubber hose was to big and hard, i guess from running the vehicle it popped off.

 

[ssbroly]

Damn, that cleared up everything?!

 

[mmellott2010]

Yes, It did, and it is running great. I cleared the codes and they never came back!! it idle's and runs smooth again.

 

[Jdbayy1]

PCV Hose

I had the same problem. Ford didn't have the 40.00 part so I removed the part and most of it is hard plastic pipe that looked brand new with insulation around it, so I just replaced the rubber ends that were dry rotted and leaking with fuel line hose for about 3 bucks from the auto store!