My check engine light came on and i took it to the shop. the paper said --manfacurer control and --Fuel air metering which im guessing has to do with the A/F ratio. my mods are aem intake, dc headers, apexi exhaust, koyo radiator, MSD ignition ex coil and cap, NGK plug wires, plugs and VAFC. my car dosent feel like its very efficient so i guess i jus need a good tune. any suggestions to what is going on and if i need a hondata, o2 or somethin like that?

I drive a 99 honda civic si B16

 

is the vafc tuned on a dyno with a wideband or did you just mess with the settings not knowing what you were doing?