i have a problem

[Thighs]

my car isnt running right, and im not too good at diagnosing these types of problems.

it loses alottttttttt of power at different rpms below 4g, but has mad jdm tyte power above 4. the idle stays between 750-1000 rpms, but after a minute of sitting it drops down to like 500. and when i blip the throttle suddenly it likes to sputter, similar to a dirtbike motor with the choke on.

to me it seems like its running rich, but i have no black **** on my bumper, so idk. MAF maybe? any advice is appreciated.

[RBS]

do a tune up and change your o2 sensor

[Thighs]

i did do plugs on it the other day, but no change was noticed. oil change not long ago too.

you think its the 02 sensor? ive been told TPS and IAC too... so idk.

[StraightSix]

IAC will usually not cause any problems except at idle. The car will usually die at idle because there isn't the right amount of bypass air for the engine to continue running. Off idle and under load the car will run just as if the IAC was fine.

TPS will be dependent on throttle position. The TPS is basically a potentiometer so, the resistance value it sends back to the ecu varies. The contacts inside the TPS will eventually wear out, but it usually happens in the partial throttle range since that's where the throttle is for most street driving.

[RBS]

it MAY be o2, im not sure but im thinking about my little cousins k20... he has 2 bad o2 sensors and it runs like poop below 4500 but after that its over