I went by autozone and i was told it was probably the MAF. I used the special cleaner, however it didn't help.

the truck cranks up fine, and will even idle while cold for a short time. However when it warms up, the rpms drop down to where it'll go dead. It runs just fine when the wheels are rolling.

is there anyway to tell? i hate to spend $100 on a hunch. and i hate to bring it in to a dealer and get reamed for XXXXXX$$$$$, you know how that goes.....

thanks in advance

2002 F150 2x4 4.6 Triton

 

To get advice, you need to let everyone know what year and what engine.

 

#1 what codes is it throwing?
#2 why are you driving a truck risking your engine if you think the MAf is bad???

 

it'll hurt the engine, really.... Didn't know that if so.

i'll go back and get the codes, he just told me it was "1 and 2", and that was usually the MAF.

as above 2002 F150 4.6 triton 2x4

 

1 and 2

 

Have the codes checked first to see. I don't think you have a bad maf.

The vehicle uses the cold start fueling map (choked) when it is first started, so it will overcome some problems with the addition of fuel until it exits the cold start cycle. It sure sounds like a vac leak somewhere, or possibly worn front O2 sensors??

You can run and drive with the maf disconnected.
Good thread........
http://www.explorerforum.com/forums/....php?p=2349680

 

I would clean the IAC and check for a leaking IAC hose.

 

Stop back by Auto Zone. Ask them to scan it again for you, - write the codes down from the scanner. Write exactly what the scanner says, - tell them you want to see the code (or cods). DTC's to be exact. Take a pencil and paper with you.

 

P0136
circuit condition (heated oxygen sensor bank sensor 2)

P0156
same as above

P0171
trim bank one condition

P0174
fuel trim bank two condition

P01131
lack of bank 1 02 transitions - lean explanation

p01151
lack of 02 switches bank 2 sensor 1


my truck has 200,000 miles on it, if that helps any. never any problems before.


thx again.

 

P0136~ Heated O2 Sensor Circuit Malfunction (Bank 1, Sensor 2)
P0156~ Heated O2 Sensor Circuit Malfunction (Bank 2, Sensor 1)

REAR SENSOR FUNCTION

The rear (downstream) HO2S sensors are treated rather differently. The peak and low voltages are also continuously monitored, but if the monitor has not detected a peak or low voltage beyond threshold, then the fuel/air mixture is forced high or low in order to get the sensors to start switching. If this sequence does not 'shock' the rear sensor(s) into switching, then a DTC is recorded.

P0136 - No activity Bank 1

P0156 - No activity Bank 2

Typical voltage thresholds are Rich <0.25 to 0.50 volts and Lean >0.40 to 0.65 volts.
__________________________________________________ _______________

__________________________________________________ _______________

P1131 ~ Lack Of HO2S11 Switch - Sensor Indicates Lean
P0171 ~System Too Lean (Bank 1)
================================================
P1151 ~ Lack Of HO2S21 Switch - Sensor Indicates Lean
P0174 ~ System Too Lean (Bank 2)
__________________________________________________ _______________

FRONT SENSOR SIGNAL

The Front sensors are tested continuously for switching during Closed Loop operation provided the Conditions are met. Excessive time between switches, or no switches, indicates a malfunction. Since the lack of switching could be caused by fuel trim shifts as well as a sensor malfunction a stored DTC indicates whether the sensor was always indicating lean or rich when it stopped and if the Fuel Trim was at max.

Where Lack of Switch DTCs are recorded the LT Fuel Trims should be watched closely - if these show well into the negative or positive at idle they could be caused by an air inlet leak or a faulty Fuel Pressure Regulator - meaning that the fuelling has not changed rather than the HO2S not detecting it. Before changing front HO2S sensors Pressure Sensor and Sample Scan first - particularly if there are any starting issues.

DTCs

P1131 - Lack of Switching - Sensor Indicates Lean, Bank 1

P1151 - Lack of Switching - Sensor Indicates Lean, Bank 2

 

so what should i do? thx

 

I have an 01 f150 5.4L that is having starting issues and has popped the codes po1151, po1000, po0151. I had pepboys check it and said it was a bad o2 sensor front driver side. Truck has issues starting every now and then. Changed o2 sensor but problem still exists. I have checked for a vacuum leak and found nothing but noticed a strong fuel smell after attempting to start truck. Pepboys could not dupicate the no starting problem and just told me it was the o2 sensor. Any suggestions as to what it could be.

 

 

I think the parts monkeys first fix is you need O2's.. Sounds like the OP needs to check the PVC elbow at the back of the throttle body..

TFJ150 your problem is unrelated sounds like you have a bad coil or plug. Maybe time for a tune up.