Hey all, my wife's 2009 Corolla has been taking a few turns to start. There's misfires in every cylinder, and the engine shudders.

It was running fine when we got it around a year ago, and the problem slowly came about. I've replaced every ignition coil and spark plug, and they're all firing fine. Then I thought it was oil getting into the spark plug wells, so I attached a straw to a shop vac and stuck it in each one (not much came out), then replaced the valve cover gasket.

It seems to be a fuel issue, but my fuel pump seems fine. I was thinking maybe it's sensors, but I'm really lost and I have got to keep this vehicle running! Any advice would be welcome.