98 E-250 Rough Idle; codes p0156,p1131,p1151,p0301,p0171,p0174+

O2 sensor po136,front and back sensor to be replace.

P1151 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 2


p1131 p1151 p0171 p0174 p1131 p1151 p0171 p0174
All of these p1131 p1151 p0171 p0174 codes indicate a problem with a lean condition. This engine is known for vacuum leaks, so before you start throwing oxygen sensors at the problem, it pays to perform some diagnostics.
Start by cleaning the MAF sensor. Spray the sensor with CRC MAF sensor cleaner. Next, check the plastic vacuum lines, especially where they meet with rubber boots. If they are cracked or the rubber is swollen, replace the line. Then check the rubber elbow that holds the PCV valve. That elbow is a know failure point. In fact, the entire PCV tubing is a trouble spot on these engines. (thanks Ford).
After you've checked for vacuum leaks, check the operation of the oxygen sensors. The easiest way to do that is to disconnect the sensor from the harness. Connect one lead of your digital voltmeter to the black wire on the sensor and the other lead to battery negative. Then start the engine and add fuel (either propane, starting fluid, or carb cleaner) into the throttle body to force the mixture to rich. You should see a corresponding increase in voltage as you add fuel (from 0 volts to slightly less than 1 volt). Start and stop the fuel enrichment and watch the meter to see if the volts drop as you stop adding fuel. If you see no change, the sensor is dead. Replace it.
You can also use the fuel enrichment procedure to locate intake gasket leaks.
P1131 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 1
P1151P1151 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 2
P0174 system lean bank 2
P0171 system lean bank 1


This is the only info that didn't come back directly to FORD (yet still mentions it) instead of GM. Not to sure you got the correct code.

sounds like you got a smaller amped alt then what was there.

P1131 Lack of HO2S-11 Switch ,Sensor Lean
P1151-Lack of HO2S-21 Switch ,Sensor Lean
PO171- System to Lean (Bank 1)
PO174-Systen to Lean (Bank 2)

Fuel Filter -Plugged
Low Fuel Pressure
Evap System -Leaks
Leaks - in ducting,air filter to throttle
PCV -Leaks
Exhaust System -Leaks
O2 Sensors-worn out

USE THE MORE EXPENSIVE FUEL INJECTOR CLEANER , CALIBRATION NEED ON NEW SPARK PLUGS AND U WILL SEE THE DIFFERENCE. AVM([email protected])

Change plugs, and Mass Air Flow sensor. This should do the trick

P0301 = Misfire cylinder #1P0303 = Misfire cylinder #2
P0171 = System too lean cylinder #1
Are you sure on the P1151 code? I am thinking this may be a P0151 which is O2 sensor related.
This looks like you have a fuel system related misfire. I would do a fuel injection cleaning service and then clear codes and see if the codes regenerate.

in the center of the motor,in the rear on the fuel rail

Hi, since the check engine light (CEL) is on you need to get the trouble codes read. Most auto parts stores will do this for free. If there isn't one nearby, any shop should be able to read it (for a charge) or you could buy your own code reader.

The code(s) you'll get will be in the format PXXXX like P0171 or similar. Once you have the codes you can look them up here to get a description - http://www.obd-codes.com/trouble_codes/

Or post the codes back here and we'll help you out. The next step is to get those codes though so you know exactly which areas of the engine to concentrate your diagnosis efforts on. Good luck!