07 Corolla misfire (idle in drive and reverse) with no check engine light.

I have searched and searched and I seem to have found nothing. I originally had CEL for a Lean trouble code, and a miss fire. Here is what I replaced, spark plugs, intake gasket,fuel pump, MAF sensor, 02 sensor. None of these fixed the issue. I then replaced all of the injectors and the code has gone away. Here is the issue, now I have a misfire at idle and while slight pressure is on the pedal while traveling. There is no CEL!!! I removed the throttle body and cleaned it very well, I searched for a vacuum leak with sprays and propane. No leaks. I understand the mounts on these model cars tend to fail and trigger issues. On my issue I can see the rpm's drop before the actual miss occurs. Thats why I am leaning away from the mounts, the bad mounts shouldnt make the RPMs fluctuate. I do sense a small exhaust leak by the donut on the manifold. I also have not put new coils in. I decided not to put the coils in because I assume there would be a CEL on for a bad coil. Does anyone have any suggestions?

I have a 2003 Corolla LE, 250K miles. Same problem. and all you have described was done to the car. All ignition coils were replaced. There is not a code right now. Our mechanic also advised to replace the engine mounts. However there is loss of RPM, but. I've noticed this when the AC was on.