I've had this (limp Mode) problem since Sunday afternoon. The half engine light, the check engine soon light, very hard starts after sitting for a few hours, sputtering, knocking, you name it it's happened. Did what little i could. Checked vacuum tubes, read and reset codes, had been using Shell gas which didn't run well in my car. That's when all the problems started. Did a complete fill up with BP which works great in my car but still no love. If i drive on 40mph my car has a shit fit.
Taking it in Wednesday morning. I'm not looking forward to this it doesn't sound fun. It's a complete buzz kill.