For a 2K GTP with 157K on it I'd rather not take the chance of wiping the sensor off and having it fail again shortly thereafter, thus leaving me stranded somewhere and adding a huge towing bill to the mix. These are known failure parts on these motors. For the amount of work that goes into getting to it I'd spend the $40 on a new sensor for piece of mind alone. I've never heard of just wiping it off and having it work again, but then again new things everyday, right?
BTW, the CKPS on my 95 Bonne didn't have anything on it when it failed. It was as clean as the day it was installed yet died just the same. The only reason I noticed this is because it was strange how clean that area was compared to the rest of the motor. Electronics are great, when they work, lol...
And as far as getting it scanned, maybe a Dobbs or the like can do this for you. I know the dealer can, but like I said they will want to charge their diagnostics fee, which around here is about $80.
Most of the OEM ones I've seen/tested just (very obviously) had the filings build-up issue. The engine pictured above is not a 3800SC Series II it is missing the second little harness plug and cam sensor on the upper left side of the crank.
