i have a 99 civic si DOHC v-tech and i have been having a problem recently with it acting like its runing out of gas some times or the rpm guage going all the down making the car almost die ive checked my spark plugs and they all have spark but my checkl engine light just came on not to long ago, maybe its a fuel filter? what else would do this?

 

First of all v-tech is a type of cheap ass phone, your car has a VTEC system.

What you need to do is find the OBD II diagnostic port on the right passenger side foot well (should be a green or blue plug with nothing plugged into it) stick a paper clip into it between the two sockets, turn your ignition key to on, and count the series of flashes. For example it could flash 4 times then pause and then 3 times....that would be a code 43. Find out what code the ECU is throwing, then look it up and that would be a start in diagnosing the problem. Might be your O2 sensor....but check the code. I doubt that it is your fuel filter, but anything is possible...good luck..