That is exactly what happened to my Fusion Sport with the stock turbos as long as 2 years ago. The first few times it happened I was trying to diagnose it but no one here ever encountered it or didn't bother to comment on my posts. But when that MIL flashes, the trans often stops working - it goes into neutral and I can use the paddles to up/downshift but nothing happens and I'm stuck in "neutral." I wasted a lot of time looking at the transmission. That was very early on. More recently it'd shudder very badly, or just stall out at the light. Drilling the weep hole and blowing out the "cobwebs" helped, and the new plugs helped as well. My 2014 SHO never had these issues even at 30k miles of hard use with a tune, and dozens upon dozens of WOT runs/track runs. Oil was basically spewing out of the rear turbo on that 3.5 and everything just ran like clockwork. Weird.I'm having a similar issue with my car after the MKZ turbo swap. I don't have methanol, but I get occasional high RPM misfires, only on cylinder 6. I seem to be able to duplicate the issue most easily when in Sport mode and going WOT around 60 MPH. If I go WOT around 60 MPH in Sport mode, the car will downshift, run through the RPMs, go to shift up, but downshift instead and bounce itself off the limiter. Once it does this, the MIL flashes, cylinder 6 is deactivated, and the car runs like crap for a minute or two until the PCM starts firing #6 again. You can't really feel the misfire until the MIL starts to flash, but car does feel down on power a bit until it bangs off the limiter. I have tried swapping plugs and coils between cylinders to see if the misfire follows and it doesn't. I also had the dealer replace the #6 injector under warranty and it didn't change anything. I gapped the plugs down to .024 incase there was spark blowout but that didn't resolve it either.