Rep Power: 0

2002 Civic EX with manual trans.

Car starts and idles fine when cold but once warm when closing the throttle the RPMs drop to 500 then back up to 700 where it stays but the idle is rough. Can feel it and see it in the steering wheel. Issue is worse with AC on.

No trouble codes either active or pending.

The following solutions have been attempted with no correction to the problem.

Timing belt, water pump etc was replaced and I have verified the timing marks are correct.
Throttle body removed and cleaned with new gasket used on reinstall.
IACV cleaned.
EGR cleaned.
New plugs and air filter.
Idle relearn performed.

Did not replace coils. Does anyone know the test procedure for them?

On another post someone mentioned that low voltage in the battery / charging system can cause issues so I check mine.
Battery measures 12.75 volts when car is off. Measures 14,17 volts with car running and interior fan on high but with AC engaged the voltage drops to 13.32 volts.

Could my alternator be on its way out?

Can anyone check their voltages for me using the same 3 testing points so I can compare?

New belt installed during timing belt change and seems tight to me.

Any assistance would be greatly appreciated!

Thank you