Ok, no matter what I say, y'all won't believe this...I've got a 93 2.0 with 120k spotless miles, low-res exhaust, and different intake, 5spd. The car will run all day at 125mph. BUT, the speed limiter only works when the cruise is ARMED, not active, but just ARMED (button on the dash is on). Make sure you didn' t accidentally leave your cruise on! If this is something that happened suddenly, maybe that's it. I figured this out on accident trying to chase down another mx-6 on I10 - with the cruise on, it runs to 115 and cuts off the fuel.