codes p1131 and p1151 HELP

[darkside03gt]

today while driving i noticed that my wideband was reading 15.0-15.5 at idle. didnt think much about it since i had just installed a tune from my tuner and figured the adaptive was trying to figure things out because i've been told that after a re-flash the ecu will test the sensors a little. well i was sitting out side my apartment complex waiting fo the gate to open when the check engine light came on. I pulled the codes and came up with p1131 and p1151 wich says both bank one and two sensors read lean. i have done some searching and found out that this doesnt mean the 02 sensors are bad. I dont have a vacume leak because my boost/vac gauge reads a hair under 20 inches witch to my knolege is normal. Can someone please give me some probable cuases or things to try? Iam trying to aviod taking it to the stealership since it is 110 just to diagnose.

 

[HOOCBB]

Mine set the same codes a couple of weeks ago. I couldn't tell anything from the freezeframe so I reset the light. The same codes immediately came back, so I reset it a 2nd time. It seems to run fine and the code hasn't come back.

I know that doesn't help you much right now, just thought I would throw it in.

I don't know what the A/F should be at idle, but if you feel there may be a lean problem, check your fuel pressure, change your fuel filter and clean the injectors. Of course, you could also go back to a previous tune and see if it still sets those codes.

 

[cooper]

I just gave up! ive had the p1131 for 2 years and drive every day with the cel on. Havent found a cure yet, if i reset it the car runs like pure crap until the cel comes back on????? I wish the cel bulb would burn out , its tough as nails. never had the 1151. Ive changed the front o2 sensors twice, still get the 1131! so i just live with it.

 

[darkside03gt]

since i have installed the prevouse tune the wideband has been really jumpy either the computer is testing things out or its getting ready to throw the codes again. if i can get a good deal on some OE 02 sensors i will first replace them because according to a ford service manual the upstream 02 sensors are to blame. so we will see.

 

[62thunderbird]

My Mustang did the same code p1131 lean and I reset it and it has not come back on and it has been 4 months. Since you put a tune on the tuner maybe the computer is confused. Maybe you should reset it and watch to see if it comes back on. Sometimes the computer reads something wrong.

 

[usmcv8stang96]

from a mechanic

hey guys i have goin thru same problems right now!! i blew a heater hose and it brought up these issues.... the vacuum hoses close by were very old and had been split off by the pressure ive read some forums and they are all saying different things ford says its the 02s but i only have 2 in cause i have custom exhaust so i dont believe it i fixed my oldest hose it got rid of a 1131 i think its something to do wth vacuum in the engine ill keep u all posted on what i come up with

 

[peepeeskillz]

i have the same problem too. first i had it with my o/r x-pipe and it turned out to be an exhaust leak after i fixed it i didnt have the problem anymore. then i got LTs and didnt have the problem for a while until i hit my mid-pipe on the ground a couple times, and the code came back, and im pretty sure it is because of an exhaust leak, i can hear it when i drive next to a wall.

 

[wmburns]

There is a HUGE list of things that can cause this DTC. Simply doing a reset is not going to make it go away.


Electrical:
Short to VPWR in harness or HO2S
Water in harness connector
Open/Shorted HO2S circuit
Corrosion or poor mating terminals and wiring
Damaged HO2S
Damaged PCM

Fuel System:
Excessive fuel pressure
Leaking/contaminated fuel injectors
Leaking fuel pressure regulator
Low fuel pressure or running out of fuel
Vapor recovery system

Induction System:
Air leaks after the MAF
Vacuum Leaks
PCV system
Improperly seated engine oil dipstick

EGR System:
Leaking gasket
Stuck EGR valve
Leaking diaphragm or EVR

Base Engine:
Oil overfill
Cam timing
Cylinder compression
Exhaust leaks before or near the HO2S(s)