I have had p0455 go on and off for the last year or so, usually fixed for a while with a new or tightened gas cap. I took it in at one point and they said there was a crack in my vacuum system somewhere- and it was fused to the carbon canister so they would have to replace both. I did not get the repair because it was too expensive at the time. Now I have this new p1140 code that is for the intake valve timing sensor. The person at autozone told me the codes were probably connected to the same problem. Can someone maybe tell me what this could be? are they connected? can someone give me an estimate on a repair before I take it in?