I just had a positive experience with resetting the PCM's adaptive numerator using the instructions from @Wombat
I had recently replaced the OPDA and camshaft position sensor due to a P1391 CEL at high RPMs (there was excessive, lateral play in the OPDA that caused the sensor ring to wobble at high RPMs which damaged the camshaft position sensor).
Soon after, I began getting a new CEL for random misfire (P0300) together with a couple of cylinders (P0304 and P0306), but only at high RPMs.
I had recently replaced my spark plugs with a model recommended here, and I felt like the engine was running fine (sounded smooth with no signs of misfiring, etc.). I double-checked those spark plugs for gap, etc., but still got the codes. I decided to try the reset to force the PCM to relearn from scratch, and the misfire codes went away. I have test-driven it several times at high RPMs and the PCM no longer sets any CELs.
I had recently replaced the OPDA and camshaft position sensor due to a P1391 CEL at high RPMs (there was excessive, lateral play in the OPDA that caused the sensor ring to wobble at high RPMs which damaged the camshaft position sensor).
Soon after, I began getting a new CEL for random misfire (P0300) together with a couple of cylinders (P0304 and P0306), but only at high RPMs.
I had recently replaced my spark plugs with a model recommended here, and I felt like the engine was running fine (sounded smooth with no signs of misfiring, etc.). I double-checked those spark plugs for gap, etc., but still got the codes. I decided to try the reset to force the PCM to relearn from scratch, and the misfire codes went away. I have test-driven it several times at high RPMs and the PCM no longer sets any CELs.