Nothing so great about Calgary - both dealers are owned by the same people, so there's no competition between them.
I'd be looking at the plugs if it was mine, plus trying another gasoline vendor. And the comment about 93 octane being required: give me a break. 91 is plenty, but PetroCan has 94 at most places. Octane defines resistance to knock - any more than the engine needs is a waste of money as all grades have the same BTU/lb.
Good luck with your car.
Last edited by audiophool; 10-13-2012 at 08:52 AM.