can anyone tell me what this is
 

because theres oil in it and ive heard the crystal inside of it makes sure no oil comes in the sensor and when it goes bad youll see oil in the sensor... oh yea notice the oil to the right of it..

http://xd3.xanga.com/c59f074342c3222...w172838240.jpg

I bet its yer oil pressure sender.......disconnect the wiring and see if you still show oil pressure maybe

when i disconnect it the check engine comes on...but theres oil inside the sensor..

so is yer oil pressure reading showing ???

is this sensor threaded in or does it have a hold down tab with an O- ring seal

it has an o ring and its still showing....

I would pull it out and get a new O-ring to seal off the oil leak

it must be a sensor for something else if yer still showin oil pressure

maybe is it water temp?

well it goes right on the head... but ill try a new o ring first

Its your ICP sensor... So there is no oil in the connecton? Might pull it and check the O ring, but if there is oil in the plug the sensor is done. Its what tells the PCM how much ICP is in the rail.

not sure how many miles you got on you rig but i would just change it out with a new one there is an updated design
steve

Once theres oil in that sensor its done and you need to replace it. They even have a pig tail wiring kit to replace the electric plug part of it as well if you got oil up in the wiring harness. Warning its not cheap I think dealer cost for me was around 160.00.