Reaaaaaaally rough idle

[CUR53VT]

So with the help of some legends here, the car is now running and not stalling. As much. Problem is its idling really rough. I managed to reverse it out of the driveway, but in park, neutral, and all gears symptoms are the same. Ac on an it's still the same. Foot on the brake, same. Could the earth on the back of the head on the passengers side contribute to this? Had the heads redone and they came back painted. Stupidly didn't sand the spot back. Also, passenger side head, in between the front two injectors, in the cut out part of the intake manifold, there is a bold hole there with nothin in it. The bolt hole is in the head Could this cause a vacuum leak or wouldn't it go through the head walls. This car has me stumped.

[Mick1988]

Maybe pull each lead off the plug one by one and see if one of them doesn't make your idle any worse. Will help you determine if you have an electrical problem.

If you determine it's on a certain cylinder, maybe swap the plug with another cylinder see if the problem moves. If so, new plugs.

Swap two coil packs around and see if the problem moves. If so, new coil packs (all not just the 1)

If it's still dropping that one cylinder, change your plugs and your leads.

Probably your best bet.

[wrx884]

do a self diagnostic test and see if u can rule out a EGR fault.

[CHA53R]

Did the throttle body come off at all?

[CUR53VT]

Faults that came back were 47 and 49, crank sensor signal. Rang Holden and they said this wouldn't cause the problems I'm having. Or explain why I'm using close to 1l of fuel per kilometer. Throttle body came of but has new gaskets, cleaned out and alla vacuum hoses back on at both ends