Camshaft position sensor location?

My 2002 Ford Mustang 3.8L mustang with 64,800 miles is having an issue with the Cam Positioning Sensor (CPS). While I was driving, it started stuttering, like I put bad gas in it. Then a few miles later the check engine light came on. I drove it straight to Advance Auto Parts and had them hook it up to the computer. The computer said it was the CPS. I tried to drive it the next morning and it worked ok then it started really stuttering. Literally felt like something was grabbing the pulleys/belt and stopping it then letting it go again. Eventually, it stalled completely and wouldn't start again for a few hours. After I started it would stall any time I'd stop. I replaced the CPS and it is still doing the stuttering thing anytime I go over about 1500 RPM's. I have checked the coils and all the cylinders are firing. What could the problem be?

I replaced cam synchronizer and position sensor. I bought a tool set to align synchro but I don't know which one to use. There are four colors, gray, black, blue, and yellow. Which tool color is correct?

Electrical problem
2004 Ford Mustang 6 cyl Two Wheel Drive Automatic

whare is the camshaft position sensor and if its bad could it cause a squeeling noise?

Is that the same on the 3.9?

Where is it located at/