Hi,
I have just had a similar problem; it was also very sluggish at low revs in first and second gear. The orange engine light eventually came on and stayed on, I took it for a diagnostics check and they told me it was the cam sensor. To replace the sensor and the diagnostics check it was £120; the test on it's own was £30.
That was 4 days ago, today my timing belt has just gone and I have been quoted at least £200 as long as the valves etc have done no further damage to the engine.
Seven days ago I was going to trade my Vectra in for a Ford Focus!
As soon as it's fixed I will be waving goodbye to it.
Good luck with yours, I hope you don't experience similar problems.
Stephen
July 2005