I have been a fan of your show for years. I have heard you solve so many puzzles and finally have a puzzle for you.
I have a 1988 Toyota pickup 4x4 5 speed with the 22re (not the 3.0L Thank God!!!). I have a miss only when the vehicle is at or near operating temperature, it is sitting still(not under power) and the RMP is at about 2000 or higher. It is a definite miss which is what is keeping me from smoging this P.O.S 9000 and selling it. I am just out of range with hydrocarbons and completely in range in co2. When driving, no miss is detectable.
What state tests vehicles at 2000 RPM under no load??? This testing procedure is COMPLETELY invalid because they are failing you for a condition that does not exist in the real world.
I suspect your EGR valve is opening (as it’s supposed to) but under the no load condition is causing a slight mis-fire. Disconnect the valve and see if it smooths out.
When was the last time the O2 sensor was replaced? Toyota recommends replacing every 30,000 miles. I can tell you from experience that the 88 ODB system doesn’t check for proper O2 sensor operation, just that it has continuity with the O2 sensor, meaning that it is there. If the O2 sensor is bad, slightly high HCs are common problems.
These can be tested before you replace it. Once warmed up and running, the O2 sensor should produce a voltage between 1V and 5V. If you need to replace, I recommend buying a Toyota sensor, since I tried aftermarket sensors from Autozone with bad results.