touched ovp w/screwdriver-"click" what broke?

[ericzacha]

Alright, first of all let me apologize to all my forefathers who taught me better. I have a 1988 300 SEL 92,000 miles that recently had the CEL come on. Car was running okay except for RPM oscillations (500-800) and rough idle at stop signs and not a lot of power. I have read quite a few threads on both the CEL and rough idle. Have a CA car and the diagnostic code was #4 which I understand to be the air flow potentiometer. Anyway, thought i'd check out some of the simple stuff first. Changed cap, rotor, and plugs. Cleaned up the ICV, throttle linkage, and microswitch. Thought I would take off the OVP and shake it to see if it "rattled". Had a little trouble getting it off. . . used a screwdriver. ....accidently touched a pin or two and heard a couple clicks. Replaced OVP, started car, and so far nothing is wrong. OVP fuse is ok. Car seems to be running a little better, still with rough idle, but no RPM variations at rest. The odd part is that the CEL is now off and when I check the code it gives me #1 for no codes. My question is, what if anything could I break by shorting the OVP? Is it possible that I shorted the ECU and that is why the CEL went out? If everything seems to be running fine, should I just ignore the pop/click I heard? Last of all, how specific are the CA diagnostic codes. Is it possible that with my simple fixes I corrected whatever was making the CEL come on and I won't have to replace the pot?
Any thoughts would be appreciated.