Re: Total power loss on freeway - 2003 Civic EX
I never definitively figured out what was making my Civic do that at highway speed. From what I read about Honda's VTEC system, is that among other things, it checks to make sure your oil pressure is high enough to engage VTEC. My best guess is that since I unknowingly was low on oil, VTEC probably had enough oil pressure to activate, but then after a while deactivated itself when the oil level dropped enough - resulting in a big loss of power. Since I've been keeping up on my oil level, I never experienced that problem again. I still have a feeling VTEC isn't to blame though, but I'm stumped.
As far as my CEL, I didn't bother changing my gas cap since the fuel tank is still pressurized when I go to fill up. I did change my evap canister though, since I read that topping off your fuel tank enough times will ruin the canister - throwing code P1457. After changing the canister and clearing the code, it returned 2 days later anyway.