My top gasket cover is leaking oil. I replaced the whole cover with a new one but the problem persists. My car is a 2007 Opel Astra gtc turbo

NON USA car, Non USA smog but sure easy
first off look up how PCV works
PCV VALVE HAS VACUUM ON ONE SIDE
AND THE OTHER END, GOES TO VC (VALVE COVER)
AND SUCKS ALL THAT NASTY BLOW-BY IN TO THE TB AND BURNS IT UP TO CO2.
A CLOGGED PCV IS BAD CAUSING HUGE PRESURES IN THE ENGINE , CRANK CASE.
THIS CAUSE OIL LEAKS AND LOTS OF OIL CONSUMPTION
SO WE DO REPLACE THE PCV AT 50 TO 100K MILES (USA)
IT IS A SERVICE POINT.
TAKING THE OIL CAM OFF SURE IT SOUNDS DIFFERENT
YOU JUST ADDED A BUNCH OF OXYGEN TO THE PCV PORT.
SO IS 100% NORMAL THAT, FOR SURE.
clean the PCV valve and make sure the PCV vent hose too is not clogged. there are 2 hoses on PCV
one to Intake man.
one from air cleaner intake to VC.

fix door windows problems, find a shop that can fix that.
or scan the PCM for , DTC errors.

when you say replaced the top, do you mean the head gasket ? if so have you retightened the head bolts as is the normal process , if the leak and power loss is still there after checking head bolt torque then will probably need to renew the head gasket again and check for anything that might stop the gasket sealing correctly

when you put belt back make sure timing mark is aligned / in correct spot

Is this correct for your vehicle below :
Opel Astra GTC 1.9 L 2006 model
Who puts out Opel Astra ? Is it Nissan, Ford, Chevrolet etc.
Let me know

Sounds like a dead starter to me. You could pull it out and try cleaning it really well it some penetrating fluid as it could be just stuck, but if that doesn't work then it will need to be replaced.

umm yeah..

F means the sensor has failed. as to what sensor you need the codes to be read to find out witch one.

Whoa! I'd be looking for a new wiring harness and an independent mechanic to install it.

You either have a blown head gasket, or your valve seals are leaking. Is oil in your anti freeze? if so, its a head gasket issue. The only solution is to replace the head gasket and valve seals.