Been trying to clear and fix error code p0301 on 1997 Honda Accord

"Have a 1997 Honda accord LX 4 cyl. Been trying to clear p0301. Replaced spark plugs, wires, dist, rotor, pcv, and cleaned the egr. When the car is cold, start up and idle fine until it warms up. Then it idles a little rough. drives fine until you stop at a light, then I have to keep the rpm up a little. Could it be the TPC sensor?
please help

Asked by for the 1997 Honda Accord
Do a mechanical compression check on all for cylinders. You should not have more than 20% difference in PSI between all cylinders.
2 more answers
Follow #1& #2 and also might check valve adjustment.May be a little to tight.
Agree with PARTS GUY. Also vacuum leak or fuel injector # 1 cyl. Maybe!