Very likely when one runs this badly, the CEL will come on and the code might be a clue to the problem. Make sure that your CEL works, it should come on for 2 seconds when you turn the key on but don't start.

The abnormal shifting seems to be a useful clue, maybe the throttle position sensor is telling the ECU the pedal is floored when it is not. That will also affect the performance of the engine.

Things that can cause low horsepower but no CEL also include wrong timing (timing belt skipped) or a clogged catalytic converter. But neither of those are going to change between being cold and warmed up. So I suspect its a sensor problem.

 

Is there any there any other way to tell if it's throwing codes if the cel doesn't work? Cause I haven't paid attention to what it does when you turn the key on. Also, being cold or warm doesn't affect how the car runs, it runs the same regardless.

 

You can always read the codes with an OBDII scanner. That is preferable anyway since more detail is available with a scanner than the blinking light method. But do make sure the light works, it is useful sometimes.

 

I have a scanner and it's only throwing the code for the knock sensor.

 

1) Replace the plugs, wires, cap, and rotor with OEM and check the ignition timing with a timing gun.

2) Drain and refill the transmission with Honda-recommended ATF. Then repeat.

3) Check the input and output voltages from the TPS on the throttle body.

4) Go from there.