Connector C103, everything that makes an engine run goes thru this thing ie:upstream o2 signal and heater, the injector's power and return, coil power and trigger, MAP, crank and cam sensors, water temp sensor. This connector is mounted on the block going thru a whole bunch of extreme heat cycles.
It's under intake manifold above starter. remove battery and the 2 top bolts supporting intake. reach in and pop connector from its mount. Now pry manifold mount enough to pull the connector up and out, it barely makes it. Now you can seperate and clean.
WARNING If you use CDC SPRAY IT WILL SWELL the seal making it almost impossible to get back together again.
Okay, I bought my Pt dead, 2 shops gave up on it so it was cheap. I traced the problem down to this connector, sprayed it and put it back. Started right up. exactly 1 year later started dying shortly after leaving driveway and maybe restart sometime later could be minutes could be days. It was C103 again!!!!
I physically cleaned every connection, cut a piece from a emery file to fit into connections to clean. This time I left connector resting in front of manifold. So far so good.
While you're at it clean the connector C2 (I think, hell do them all) at the Power Train Control Module, it also has all the same wires going thru it. You'll be amazed at how much better the thing runs.
I can honestly say this is the smoothest running engine I've ever had. i THINK EVERYBODY SHOULD CLEAN THESE CONNECTORS JUST as a GENARAL PRACTICE.
Good luck to you all.

 

I just wanted to add.
I tracked this down because the 12 volts to the injector and coil was dancing all over the place attempting to start. You could tell when an injector or plug tried to fire. This is easy to check at the capacitor on the back of upper intake manifold.