ok, i've used basic knowledge and some tech info and i'm now down to a few possibilities on why i'm still running lean.

things i've done:

1. fuel filter replacement
2. fuel injector cleaner

outcome, still throwing the error code and air/fuel gauge is confirming this.

possible reasons:

1. Intake Air Temp. sensor (gone bad)
2. Engine Coolant Temp. sensor (gone bad)
3. Fuel Pressure Regulator (gone bad)
4. Fuel Pump (gone bad)
5. bad connection somewhere from factory harnesses (doubtful)

so if anybody wants to jump on this as i start to check these things tomorrow just go right ahead and post away. also note, i'll be using good sensors off of my buddies 99 eclipse to check and see which one of my sensors are bad. and if it's not the sensors, then i'm pretty sure it's the FPR or Fuel Pump. TIA:thumbsup
later

how many miles you got on your o2 sensor? it could be your 1st one in the dp. check that bad boy out.
Michael 99gs 8-Injector Setup
HRC Stage 2 @12psi :D
Stage 3 process begins gathering parts for rebuild
2GNT Member #32

http://www.dreamwater.net/purplebeast

i replaced it in march. so i know it's not that.
later

Don't you have a SAFC?

I would still consider the front o2 sensor. I replaced mine around march, and it was bad right out of the box. I just bought an ngk o2 and the car runs purrrfectly

that's the thing though, i'm not throwing an error code for it and i'm not getting bad gas mileage. so i know it's not that. i did notice this today:

when i left my house today, i didn't let the car warm up all the way before i started driving. but i did notice that my air/fuel readings were normal and my car had better pulling power. but once my car was at normal operating temp. the car didn't seem to pull as hard.

so i'm seriously thinking that my Engine Coolant Temp. sensor might be bad. while the thermostat keeps the car from overheating and opens for the coolant to pass through the motor, the sensor is just to keep check. so i'm thinking the sensor is bad since the car runs fine until it gets to normal driving temp.

let me know what you guys think.
later

ok, i'm taking a nap now. i checked some connections and wires from the ECT sensor and they seem fine so i still have to check the sensor itself. anymore input would be appreciated and all. TIA.
later

It could still be your O2 sensor. You said your car runs well when it's running ritch during warm up, that's a runction of the ECU but I doubt it would make it lean once it's warmed up. What are you using the SFMU? If so I would check your pressures and try to richen it a little, and if you have the SAFC use that to richen things up.

i'm still non turbo and my afc settings are at 0% until i get this solved and all.
later