my 2003 explorer runs fine most of the time but sometimes when you stop at a light it will sputter and lurch real bad it is saying lean on cyl 5 but i cant figure out why. Any suggestions

 

Start with the basics....pull your plugs on that side and check electrodes for wear or damage...unburned gases from a bad plug on that side (one or more) can cause FI lean issues on cylinders on that whole side.(the exhaust detects rich fuel from unburned gas in a bad plug cylinder...and tries to compensate by reducing fuel inputfor whole fuel injection rail...causing possible lean reading in a different cylinder)..

could be clogged injectors......run a good cleaner through your tank..

check your Idle Air Controller...sometimes they stick and cause idle issues...does it run better after it warms up? or does it start acting wierd once it warms up? could mean a stuck bypass inside the IAC..

To check...remove bolts and pull IAC off of intake manifold.....leave harness plugged in....get an assistant to turn ignition off and on a few times without starting engine while you look inside IAC....piston inside IAC should move and seal off bypass....

if piston inside IAC sticks..then gently free it up with a screwdriver and carb cleaner..dont scratch the metal or you could damage its function!! Lubricate it with WD-40 and recheck....

A stuck IAC doesn't show up in codes and is a common issue with these engines...they get clogged and stuck with black carbon buildup inside IAC....

 

thanks for the quick response. Sorry I am not real good with cars so I have another question befor I can check the IAC i need to find it is this it?

 

looks like it...it is right at the end of the air snorkle.....