Ok so i thought my car was running really rich due to sluggish and not much power, bad mpg ecu. So we put it on the dyno and come to find out im running really lean. My afr's is like 14.0-14.5. it never used to run like this and just one day it has.

My set up

1991 ef civic odb0 pr3
b16a
intake
header
catback exhaust
gsr cams

Now i was told a 255 fuel pump would fix this problem, since it has an old stock fuel pump right now.

No check engine light all sensors are good. The only thing i do not get is if its running lean why do i have no power and horrible mpg.

car does not smoke at all and idles and runs fine, just no power and lean.

 

It would be ideal if you had a fuel pressure gauge on the vehicle to determine if you were seeing fuel pressure drop on the dyno.