This is what I'm pulling out of my 2000 Expy with an Accutron OBDII reader.

Code: P1151 Manufacturer Fuel Air Metering

All my I/M monitors are good except Catalyst Monitor and Evap System Monitor, which say "Inc"

I got a Freeze frame, and this is what I read...

DTC causing: P1151
RPM: 1180
Load value: 71.3%
Coolant Temp: 188F
Short Term Fuel Trim1: 3.1%
Long Term Fuel Trim1: 0.0%
STFT2: 3.1%
LTFT2: 0.0%
STFT3: 61.6%
LTFT3: 57.0%
Veh. Speed: 42 mph
Fuel Sys1: CLSD1
Fuel Sys2: N/A



Any help? I want to see if it could be anything other than the MAF, as it's rather expensive....

Thank you!
Eric

 

Check to make sure your oil cap is on tight, the dipstick is in all the way, the PCV valve is seated all the way into it's grommet, and that the PCV hose is undamaged it's entire length.

 

Eric, I highly doubt its your MAF, as a problem with the MAF usually effects both banks.

Your P1151 is telling you that the PCM ran a test on your HO2S and the upstream HO2S on Bank 2 (i.e, driver's side) failed the test. It was stuck 'lean' at the end of the test and has not switched from lean to rich for a claibrated amount of time.

This code is keeping the Cat Monitor and the EVAP Monitor from running to completion.

Your HO2S may be dying, or the problem could be in wiring to the HO2S. (Or you may have a fuel issue (pressure, injector, etc). To save some $$, you could try swapping the left and right HO2S and if you then get a P1131, the HO2S is the culprit.

 

Thank you. What exactly are you referring to when you say HO2S? I recently replaced the #4 coil pack, and the PCV valve position sensor switch(? I think that's what it was. It was a little black box above the engine on the driver's side, it had two vacuum lines running into it, and an electrical plug.)


Eric

 

Heated Oxygen Sensor

 

That sounds to me like you replaced the EGR solenoid. It is an electrical (hence, the electrical plug) solenoid controlled by the PCM. When the PCM activates the solenoid, vacuum is passed to the EGR valve to control the EGR valve.

Are you dealing with the 4.6 or 5.4 engine?

 

It's a 4.6. Egr, yes. Egr valve position sensor switch was its name-o.

 

Well, I checked my PCV valve, and I have LOADS of vacuum at the valve. The oil cap is on tight, and the dipstick is fully seated. Looks like it's probably the HO2S? How much trouble are we talking to check those? I've got my Haynes manual, and the process it describes is not one I can accomplish in my situation. Anyone know of another way? The manual describes using paperclips or something. Doesn't sound right. Also, I don't have a volt meter. What else can I check to rule out before I replace those O2 sensors?

Eric

 

P1131 and P1151 DTCs are usually (but not always) caused by the upstream O2 sensor for the bank for which the code is posted. In the absense of in-depth troubleshooting, replace the upstream O2 sensor on the driver's side. Bosch, NGK, and Motorcraft are all good. Figure around $50-60 from a local parts store as a typical price.

You replaced the DPFE sensor. Hopefully, you got one from Motorcraft.