I had this posted in the V6 forum, but I thought more people might see it here. I have a 2002 F150 with the 4.2 V6 auto, 95000 miles. I have had the truck 2 months, and I have an SES light on. First came back with P1151 code only, changed drivers side upstream HO2 Sensor after seeing the code, and didn't fix it. Now I have codes P1131 and P1151. Now I have had diagnostics ran at the garage, and was told to change both upstream sensors. I have read enough here to know that is the wrong fix. Also have had it checked for vacuum leaks, intake gaskets, and changed out the plugs, and fuel and air filters. No vacuum or gasket leaks at all. I had lost all of my power at low end, and fuel mileage was horrible. Cleaned the MAF sensor, and got all of the power back, and fuel mileage too. 2 Days later, Codes came back, and the truck started back to having no power or fuel mileage (SES seems to come back on going down hill).Could the MAF sensor just be going bad and need replaced, or is it possible even without finding any intake gasket leaks, that I still need the Upper intake gaskets like I read about in the Tech Bulltin? I am in Ohio, and it has been running through a lot of salt in the last two weeks. I really need help because it has been draining my wallet, and I have to make a long trip with it this weekend, so any help would be greatly appreciated. Really getting desperate to fix this truck, I mean I even with problems I still love my F150, I mean I sold my chevy for it.

 

You could check the voltage on the MAF sensor. Should be as close to .99v without going over. Loosen the screws and move it one way or another to get the right voltage. If you can't get to .97-.99v, then replace it.

 

Thanks for your reply. I don't have a voltmeter to test the MAF. Are there any other tests that will show if it is going bad?

 

You have confused the MAF with the TPS (Throttle Position Sensor).

You cannot adjust the MAF sensor.

Steve