I brought the car to a friend's repair shop to use the scanner. everyone there seems to have a different opinion as to the problem. here's what i got off a snap-on solus pro scan tool.
O2 varying between 200-800
Short Fuel Trim varying between -14 to -30
In. Pulse 2.5 - 30
RPM varying 450 - 600
Fuel Ind 0%
Fuel Trim Cell 21
Spark Advance 0-20
Increasing the throttle causes the spark to retard.
one suggestion was the valve timing being off & possibly the timing chain being stretched. to check, i pulled off the valve cover again & turn the crank by hand back & forth while checking the valves for movement. there was no slop or play in the chain, the valves moved immediately with turning the crank. is it common to have to replace the timing chain on these motors? it has 171,000 miles on it.
the other guys there seem to describe the exhaust as dropping way off when the motor is revved & thought the muffler
may be clogged. I was going to disconnect it (cut it off) to prove them wrong but didn't, yet.
another suggestion was the ICM. I picked up a used ICM with coil packs from a junk yard for $40 & will install that later today, see what happens.