Check Engine Light codes need help

[gostmn26]

Check engine light came on yesterday and I bought an Actron OBD II scanner. I have a 2000 Explorer XLS V6 4.0 lt Vin X

I got 4 codes from it and are as follows.

• P1131 Insufficient Switching O2 Bank1 Sensor 1 lean

• P1151 HO2S Bank 2 Sensor 1 Insufficient Switching lean mean

• P0171 System too lean (Bank1)

• P0174 System too lean (Bank2)

From What I know and have read on here it could be the O2 sensors and/or the fuel pressure regulator. I just bought this vehicle 1 1/2 weeks ago and have an extended warranty on it and taking it to the dealer tomorrow. I would like to try and figure out what it is myself so they don't try and say well it's this and that.

Another problem I have noticed is there is a humming coming from the passenger side of the vehicle and it does it when warm or cold. It stops when I rev the engine up but then starts back up whenever it feels like.

 

[floydr007]

The humming sounds like it could be a idle air controller (IAC) problem. Very common to go bad on these cars. I just replaced mine today. Im not sure about the lean conditions, but im guessing it is oxygen sensors or a catalytic converter that are causing the problem. Ill let someone else get more specific on that because I have no idea what it is more likely to be. Good luck.

 

[gostmn26]

Well I went out and checked the vacuum lines and founf that the EGR Valve Position Sensor had one of the nipples borken and the hose that connected to it was tore as well.

I am gonna point that out to the mechanic tomorrow but also tell him what codes I had so that they don't say well you have this and that wrong.

It is under warranty for the next 36,000 so it's not a big concern but I still like to know what's wrong before I take it to them.

Thanks for the advice floydr007.