CEL wont rev past 5k rpms?

[Ugly SR]

This has happened 3 times so far. Bone stock 1989 s13 SOHC, on my way to work, run through the gears getting on the highway, revs clean pulls like stock...
A few moments later the CEL will come on, and I wont be able to rev past 5k, almost like a fuel cut, then comes back on at 3k rpms... Before I reach my exit, (in about the exact same spot) the CEL turns off, and it runs normal again.. Its done this on 3 separate days in roughly the same location.. Do you need to check the code while the light is on or does it store the code?

Any ideas would be greatly appreciated.

[Fuego]

MAF is my guess

[Ugly SR]

Thanks. A friend told me the same thing, going to check into it. Also, I'm getting horrible gas mileage. Like 80 miles on half tank??? Runs fine, no smoke, no smell of gas...but I just don't understand where it's going.