Hi. I got a astra 1.6 g and the last few months the light that looks like an engine has been on. Not the one with the car with a spanner through it. Since this light has come on the car doesn't drive tidy. It drives as if something is holding it back and lacks power and when it idle it kangeroos and often cuts out. And the revs ain't that responsive. I've done the 2 pedal test and a code came up as 0340. (Camshaft position sensor), i've changed the sensor as told from the haynes manual but it is still the same. I've checked for obvious broken wires around there but all seems ok. I also cleaned the egr valve while I was at it and that is only a couple of months old so should be ok. The light came on pretty much the same time I changed the exhaust so I took that back off to check but that seemed ok but did notice there was quite a bit of water in there. Not sure if its codansation but I drove 70 miles in it this morning and woukd have thought it woukd have been dry. I got a multimetre and would check the sensor wire but I don't know what setting it should be on and what ampage, voltage to look for. Do you have any idea what could be wrong.