I know code P1131 says its the O2 Sensor saying it is lean but what causes this and whats the resolution???????? a new O2 sensor?

 

It could be. The code is only implicating bank 1, so the engine, as a whole, is not running lean or the other bank would have a code set for the same.
The heating element in the sensor may have gone open or the connector/wire harness has an open.

 

If the heater element opens, a different code will be set.

Most likely the O2 sensor is weak and slow. It's the upstream one on the passenger side.

Steve

 

Ok I'll change the O2 sensor and see what that does.... On my dads' truck, he has a 4.6 97 f-150. The code P0401 pops up. (Exhaust gas recirculation flow insufficient detected) Whats the cause and resolution to this?

 

some people say passenger side, some say driver side????? which one is bank 1 sensor 1

 

Bank one is the bank with number one cylinder. Pass side, first o2 sensor behind the exhaust manifold. The dad's code, replace the dpfe sensor, 99.9% of the time, the sensor has gone out of range and that is it.

Robbie

 

thanks for the help everyone..... i now have anoter problem.... when i get around 4000 rpm's, my battery ligh flashes on and off. am i correct that this is the alternator? also, when i bought the truck a month ago, the guy replaced the alternator with a used one out of the junk yard. after he changed it, thats when my temperature gauge started pegging out on hot about a minute after the truck is started.......any way a bad alternator could caude the gauge to mess up??

 

I had the same problem with my altenator the light would come on at high rpm then it eventualy stayed on and the altenator took a crap so I would get a new one and try that I will almost bet thats the problem and if the alt isnt working properly it will make the gauges act funny and give improper readings. good luck

 

Hey cdp25 I have a computer scanner and i looked in my book and it say the code means Lack of HO2S11 Switches-Sensor Indicates Lean thans that it says in my book. Hope it helps