I have a 2001 ford expedition that bogs out when i put it in drive but runs fine in second gear.
DTC P0171 -
System Too Lean (Bank 1) and P0174 -
System Too Lean (Bank 2)
Basically this means that an oxygen sensor in bank 1 or bank 2 detected a lean condition (too much oxygen in the exhaust). On V6/V8/V10 engines, Bank 1 is the side of the engine that has cylinder #1. Bank 2 is generally the side of the engine that doesn't have cylinder #1.
Note: This DTC is very similar to P0174, and in fact your vehicle may show both codes at the same time.
You will more than likely not notice any drivability problems, although there may be symptoms such as a lack of power, detonation (spark knock), and/or a hesitation/surge on acceleration.
A code P0171 may mean that one or more of the following has happened:
The MAF (Mass Air Flow) Sensor is dirty or faulty. Note: The use of "oiled" air filters may cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the MAF sensors leak the silicone potting material used to protect the circuitry.There could be a vacuum leak downstream of the MAF sensor.
Possible solutions include:In the vast majority of cases, simply cleaning the MAF sensor does the trick. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstallingInspect all vacuum and PCV hoses, replace if necessaryCheck for a dirty fuel filter and proper fuel pressure
DTC P0155 - 02 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)This code refers to the front oxygen sensor on Bank 2. The heated circuit in the oxygen sensor decreases time needed to enter closed loop. As the O2 heater reaches operating temperature, the oxygen sensor responds by switching according to oxygen content of the exhaust surrounding it. The ECM tracks how long it takes for the oxygen sensor to begin switching. It the ECM determines (based on coolant temp) that too much time elapsed before the oxygen sensor began operating properly, it will set P0155. See also: P0135 (Bank 1).
You will likely notice poor fuel economy the illumination of the MIL.
A code P0155 may mean that one or more of the following has happened:O2 Heater element resistance is high
Internal short or open in the heater elementO2 heater circuit wiring high resistanceopen or short to ground in the wiring harness
Possible SolutionsRepair short or open or high resistance in wiring harness or harness connectorsReplace oxygen sensor (cannot repair open or short that occurs internally to sensor)
DTC P0161 - Oxygen O2 Sensor Circuit Low Voltage (Bank 2, Sensor 2)It basically means the PCM detected either an excessive current draw, or an open or short in the circuit powering the oxygen sensor's heater circuit. This is in reference to the Heated Oxygen Sensor (2) located rear of catalytic converter (Bank 2).
There will likely be no obvious symptoms other than MIL illumination.
A code P0161 may mean that one or more of the following has happened:HO2S heater power circuit openHO2S heater ground circuit openHO2S signal tracking (due to oil or moisture in the connector)HO2S is damaged or has failed PCM has failed
Possible Solutions:Replace HO2 SensorRepair open or short in power circuitRepair open or short in ground circuitRepair damaged connector due to tracking
Mar 27, 2012 |
2001 Ford Expedition