Originally Posted by djcgmcse
But the ECU flash did make other things worse. Now my car vibrates and shakes constantly while driving at high speeds.
I don't see how an ECU flash would do that. It sounds more like your wheels are slightly out of balance.
Current- 2016 Race Red Focus ST1
Traded In - Sedan Revolution #249 - 2012 SE Sport - ╠╬╝ - Ingot Silver - 201A - K&N w/ snorkel delete - Blox Type R Knob