2006 Holden Commodore holden commodore omega

Have your computer scanned for codes. These codes will get us in the right area for proper diagnosis. Check with your local auto parts stores as some of them will scan your cars' computer for free.

If codes are present, post them here for further assistance BEFORE you purchase any parts.

has had a computer scan finds nothing timming chain manifold had a vacumm leak was fix cleaned gasket surface both can sensors I cam sensor was faulty replaced it i have had this problem since i brought it 12 months ago doesn't get worse or anything just stays doing the same thing....would it be anything to worry about at all runs fine drivres perfect only that little miss u get when air con is on took mit for a good drive today and it didn't do that pull back so it must of been one of the spark plugs i quess

Keep me posted.

could it be a bad coil pack under load or throttle body

Yes, it could be a bad coil that breaks down under load.
It could also be a cracked spark plug (sometimes a tech might accidentally crack one when installing them).

If a scanner is used which can monitor engine data (Snap-on scanners as well as others can do this) while the engine is running (even being driven) the technician can go into the computers "history" where he will find a record of which cylinder misfired and the number of times it misfired. This would identify the cylinder at fault and from there he could narrow down the causes by the process of elimination.