High Idle + Check engine light

My check engine lights been on for a while now, and I've noticed my idle RPM's are ALWAYS sitting at 1.3-1.5k, even when the engine is warm. Before the check engine light came on they would be normal at around 700~.

Also, sometimes my car revs on its own, its weird. The revs just go up to about 3000 and go back down then back up, and continues until I turn the car off then back on and most of the time that stops it. I'm not sure if this is the same issue which is causing the high revs.

Lastly whenever I put my GPS on charge via the 12V link my battery dies when I turn the car off. Even after only 10 minutes of it being on charge. (The car is running while its charging)

Car is a 1996 Honda Integra GSI, Manual

I know I can get a mechanic to diagnose the issue through an OBD port but I've had no time due to uni + work straight after. Hopefully someone can help diagnose these issues. Thanks!

crystal ball time.
I guess the idle is your IACV is dirty
the check engine light is a bad o2 sensor
and your 12v link is a cigarette lighter.
it could also possibly be
Colonel Mustard
in the Library
with a Candlestick

Yeah check IACV, FITV and TPS.

CEL code you can check from your ECU also. Just have a search for 'CEL check' and ECU-MAN's thread should hopefully come up for you.

Thanks guys!

There pretty much telling me the same things on another forum,

Crank angle sensor
Throttle Position sensor
And some are saying that my ECU might be in emergency mode, in where it ignores all signal from sensors, thus the high idle