Z22yh engine problems

Hi all new to the site.

I've had my vectra 2.2 direct for 6months.
When i first got the car, the owner said it sometimes jerks when reversing up hill. Ok i thought. On test drive drove great. After a few months jerking started pulling of in 1st. Strange as time went on it sometimes did it and sometimes not. At first it did seem when warm it done it. On first start, the car drove great then once warmed up it jerked pulling away, lack of power also.
Anyway i looked into engine mounts, checked them on the car and they seem fine. Also looked into maf as the blame, cleaned it and notes a difference on setting off and power, but then back to normal after a day or so.
Running like a noisy tappet noise, tinny, like a pinkering under acceleration. Along with the judder.
Racking my brain, what the hell is up with this. So one day i took of the butterfly piece of the intake manifold and gave that a good.clean, put it back on. Still the same. Next was when the car was upto to temp check the bottom hose for pressure, namely thermostat stir closed causing pressure. The hose was hard. I then purchased a new thermostat, installed and now the sounds like the same as before tinny rattle noisy under acceleration, very little judder now from pulling away, but still have a lack of power, which seems worse now I've changed thermostat. Plus the temp gauge seems outta synced now. As it sits at 82-85 while driving and upto 90 idle in traffic etc.

I was thinking the tinny noise was either a knackered cat or failed gasket from cat to exhaust.
The engine sounds rough, tappety.
Judder whist pulling away is very little now.
And power is down also from before thermostat changed.
Disconnected the temp sensor on engine and fan came on. Went off eventually after reconnecting.
The car has had a service two.months ago including fuel filter.oil filter, oil spark plugs, air filter.
Full dealer service history up until last service, diy.

Can someone help as this is driving me bonkers.
 
After changing the thermostat, when the car got upto to temp, which took a very long time, the bottom hose was soft. The thermostat had opened, but looking at the temp gauge inside car it went down to 82, that's the opening temp of the thermostat, its variable and the engine coolant temp will usually be more like 3-4 degrees more so i would have thought the temp gauge should read 88-92 whilst driving not 82-4. Strange as hell. Oh and i completely drained coolant system thinking it was a air lock.
 
Top