My check engine light stays on permanently nad has been for the last 15 or so months. I've taken it to holden to mutiple times:

- The first time they said a needed a new timing chain, so i got it replaced, but the check engine light come on a couples a days later. I took it back and they said it most likely needed a eletronic system upgrade but one hadn't been released yet. They told me they would call once it was available.

- No phone call came, then car was due for 200,000km service about 10 months later. After service the check engine light came back on after a day. Took it back and they charged me again to check what was wrong. Nothing come up again, all they could say was that there's most likely a problem with the sensors and they're too sensitive now.

- I also told them that the car doesn't start on first try sometimes, they told me it could be due to worn out keys.

I don't want to pay $550 for new sensors and $280 for new keys for these problems to keep occuring.

Can anyone advise on what may be wrong with the car or if Holden is just screwing me around?