The Mégane II Owners' Club

So I bought a cheap megane a few days ago and it's got a few issues.

Horn doesn't work
Blowers don't work

Engine hunting on idle and feels powerless.

Obd2 port not working?

Today I've serviced the car, changed the plugs, removed intake manifold and cleaned throttle body which wasn't too bad actually. No improvement at all its still really lumpy.

It's got an engine warning light on but the obd port doesn't seem to be working on it.

Any suggestions at all. It was supposed to be a cheap runabout and it's turning into a mare.

Can you try another obd adaptor? If it's not working, has it been disabled/disconnected? That would make me suspicious. It's going to be hard to diagnose without it.