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Within a week after the GF owning her tan MX the engine through a code for the Camshaft Position Sensor, '21' I believe. Having no severe driveability problems other than slight hesitation on the throttle and a little chugging at a specific RPM there hasn't been anything to worry about, so we didn't check it immediately.
Diagnosed the problem a couple of months ago and came back with the CPS itself, which means replacing the entire distributor, which is outrageously expensive even at my cost at a parts store.
Few days ago I noticed that the distributor cap had arcing on plug #1, so, time to replace the cap and the rotor. After taking the cap and rotor off I saw part of the sensor itself.
Four prongs just underneath the dust guard, which rotate past the magnetic? pickup which is the sensor itself (much like the Ford EDIS system). The prongs are horribly corroded. Most likely due to age. So, a fix will be applied since the prongs themselves are removable via a screw.
I'll be taking pictures to do a write up which will follow. Rather simple fix if you ask me. No sense in replacing the entire distributor for a little corrosion.

Cost:
Negligible

Difficulty:
1 of 5

Time Required:
1 Hour

Part Numbers/Equipment:
428: Carbon Steel Brush for Dremel

Tools:
Pliers, Philips/Flathead Screwdrivers, Small Flathead Screwdriver, Dremel, Carbon Steel Brush Attachment, Socket Wrench, 10MM, 12MM, 6" Extension, Permanent Marker

Step 1:
Remove Negative Battery cable, unplug MAS/MAF connector, unplug CAS connector. Remove intake breather hoses from the intake and remove the intake pipe.



Then remove the cold air intake duct from the top of the radiator support, then the intake box.



Step 2:
Remove distributor lead wire, distributor cap, and distributor rotor. Make note of the position of the rotor as there are three ways to put the rotor back onto the pole. Then remove dust shield and the distributor gasket (which is between the dust shield and the distributor cap).





Step 3:
Remove the CPS pickups by unscrewing the screw in the middle of the rotor mount.





If necessary, mark with the permanent marker the position of the smaller CPS pickup as its mount is circular rather than D shaped. However, there is a nub on the small pickup and on the larger pickup there is a hole in which the small pickup is mounted. For safety's sake, mark the position.



Step 4:
Clean the CPS Pickups on both sides with the carbon steel brush.





Step 5:
Clean the CPS Poles with the carbon steel brush.



You'll notice that there are three screws which hold the CPS/CAS in place on the distributor. This part actually is servicable as I've already removed half of everything to get to it. A few more screws and the sensor should pop out.

Step 6:
Toss everything back together, not forgetting to check how the condition of your cap and rotor is doing while you're in there.

The Gain:
Obviously it will help keep the sensor in better condition seeing as there was quite a bit of corossion on the poles and on the pickups themselves. A quick clean job should help the situation.

Suggestions:
Not much of anything, seeing as I was on time restraints though, I could only clean the leads and the pickups. I would have much rather gone a bit further and removed the sensor from the assembly and cleaned the distributor out as well, along with any other integral components behind the CAS. There really isn't anything difficult about this fix, let alone it's like doing half a tune up on the vehicle. This fix should be available for all/most distributor engines which have the CAS/CPS integral to the distributor.