Omega poor running - jsbholden
I have a problem with my Omega 2.5 V6 Auto which my local dealer can't sort. When the car is cold it runs fine, but when warm things go down hill.

I am getting a slight missfire when the engine is under load, ie when putting foot down or going up hills(which is most the time in the peak district!). This the gearbox then also cant make it's mind up what gear to be in (3rd or 4th).

My first thoughts are to change the HT leads but someone has recommended changing the DIS unit. Both of these are expensive, so my question is which one is most likely to fail? (cars done 54K) or has anyone else had a similar problem which turned out to be something else?
Omega poor running - Sooty Tailpipes
autos.groups.yahoo.com/group/omega_owners/

There have been discussions in the past on there about crankshaft sensors causing this.

In a nutshell, I seem to recall, replace crankshaft then camshaft sensor re-route the wires of the replacement away from the alternator.
Omega poor running - smithi
Crank shaft sensor faults are difficult to detect My saw several types of fault detector including a tech 1 at a vauxhall dealers.No faults were recorded. It caused non starting on an iregular basis you never knew when. However it has been replaced twice so a known fault.