idleing problem

[91rangerxlt]

my truck idles really bad. almost like its got a really hot cam in it. sometimes it idles 500 rpm and the truck just kinda rocks back and forth. put it on the computer and it said its running lean on the left bank. the guy i got the truck from said it was one of the o2 sensors. any idea how to find wich one? its an 02 ford ranger edge with the 4.0

 

[comparini3000]

It's not the easiest/most effective method, but it's the method most available to me. Unplug the O2 sensor (don't necessarily remove it) then take a multimeter to it. The passenger side O2 sensor is accessible from the wheel well behind the engine, you'll need to take the tire off. The driver side sensor is....i'm not 100% sure and i can't remember off the top of my head...but i think it's accessible from under the hood a little behind and to the driver's side of the engine.

the third O2 sensor is behind the cat. I can provide pictures if you need it


sorry if this is too basic/inadequate, but it's about as much as i know at this point!

 

[91rangerxlt]

lol im not a big fan of these o2 sensors. i liked on my old 70 ford f100 just strait pipe from the headers lol. the check engine light is on so im still guessing its a 02 sensor. my buddy put it on his cheap programmer and it said it was a cylender misfire. im not for sure but ill get er figered out

 

[wahl_7s]

air filter, idle air control, mass air flow sensor

 

[SquashMan2009]

does it idle like that after its warm? Its probably not the 02 sensor it wont cause it to do that mine runs without any on.... Try Pulling the MAF sensor off right at the intake there and see how it runs