I have a 2003 TS Astra with the Z22SE engine. The problem I am having is the car is jerking when driving. When I plug my diagnostic tool in the vehicle speed is erratic (up to 255 km/h) but the speedo is showing actual speed. The spanner light comes on but there is no fault code logged. I have replaced the front left hub. The car will cut out and when I try to restart it there is nothing, it will not even turn over. If I disconnect/ reconnect the battery it will start and run with no problems. I have noticed that the fault returns after 170 - 190 km.