I've got the maintenance required light on, originally it was blinking upon ignition then switched off after awhile. I'm at 150k miles and the owners manual only goes up to 120k for suggested maintenance. The last time my IMA went out i tried having the codes read and nothing came up. The car wouldn't even show up on the scanner, so I wanted to get other people's input before I try and fail to have them read again. In addition to that, the IMA light was out or removed because only the check engine light was on. I was told before that the codes can't be checked if a light is out. Anyways, it's almost time for an oil change, and the car is acting funny. I've noticed for awhile that if I come to a dead stop, engine still running, and I press the gas, it feels like the car gets rear ended because it goes up from 0 so quickly. If I don't press it hard enough, the car waits several seconds before it decides it wants to even start crawling. And the engine doesn't always shut off at stop lights. It revs high when I'm going slow, less than 15, and then goes back to normal. I have trouble getting full regen while coasting, and I have before a while. Lastly, I don't think I've ever achieved lean burn mode, even while at a steady spead on a flat highway. Thoughts or ideas for potential causes and/or fixes?