Ok, i have a 1999 Honda Civic. My car is 100% stock, no mods. heres the deal: i start my car up and it runs fine. I go to work and my car is parked for 8 or 9 hours and then when i get out of work and start her up, after like 5 minutes of driving the check engine light comes on and i cant go faster than 40mph. I'm stumped. any ideas?? could it be a bad main relay/fuse??

 

Bad main relay means no fuel=no running. Check your codes first and then you'll get some more help.

 

yes, what codes are you throwing?