engine idle rpms? and...

[mazdamama]

does anyone know what rpm is normal engine idle. also, after i put all my sensors back together that were disconnected while i repaired my clutch, im left with one plug behind the engine near the firewall, and i cant figure out where it goes or what it is. it is located right next to the plugs for the o2 sensors for the exhaust. it looks like it may be a third sensor that might have been disconnected when they chopped the exhaust to do a catback, but not sure, any ideas would be greatly appreciated.

 

[shadetree]

My 94 Explorer idles around 750 rpm. On some models there is an extra connector in the place you indicated for other models with another O2 sensor. Not looking at your truck, I couldn't say for sure, but this may be the case.shady

 

[Jason_12_02]

My '02 4.0 idles at like 900rpm. My dads 94 4.0 idles right 1000rpm as well.