hello i have a code p1131. i changed fuel filter hooked a fuel pressure gauge up to the fuel rail and it had 30 pounds idling give it gas it goes up to 40 lbs then goes down to 35 or so. is this normal ? another question when the qauge is hooded up i let it sit for 5 min it still held tell bout 15 or 20 min then it dropped to 0 lbs not sure if it was becouse of the gauge it dropped is this normal ? later when i start up i will let it sit with no gauge on and see if it still has pressure and fuel rail after 20 min. also my truck still pings when you are going up a hill and getting on it . i checked for vac leaks by spraying starting fluid on all vac hoses and egr valve and intake and air cleaner set up by motor didnt rev up like a vac leak would do . would a o2 sencer cause the pinging ? sorry for all the questions thanks kelly

 

Fuel pressure indications you describe sound fairly normal, so I would say pressure regulator is doing it's job. Fuel rail should hold pressure for quite some time after engine is shut off, but not forever. 20-30 minutes is fine. Less than 5 minutes might indicate some leakthru but even if the fuel is going into the vacum line, it will not cause a lean O2 code like you have( that would cause a rich code both banks).
This pinging issue is most likely directly related to the lean O2 code. Fix the code and you will in all likleyhood fix the pinging also.
If you ONLY have a lean code for 1 bank, then I would be highly inclined to look at the O2 sensor for that bank. You could try swapping sensors and see if the code changes to follow the sensor, before shelling out money to replace one.
If code does NOT change when swapping the sensors, then you are back to looking for a wiring problen to the sensor, vacum leak on that side or a partially clogged inector somewhere on that side.

 

i fixed the o2 sensor it didnt fix the pinging. i ended up getting another mass air flow senser and that fixed the problem. and the code 1131 was from the o2 senser i switched sides and got a lean code on bank 2. thanks kelly

 

Thanks for letting us know what fixed it

 

thats not a problem i figured if i did some one else could find it in a search and hopefully it will help them to like it did me thanks again kelly