3400 RPM and it sputters and misses??

[andrave]

Alright I drive an '89 s13 hatch back with the stock ka24e engine and a 5 spd manual trans.
When I drive at anything past half throttle, the engine misses incredibly bad past 3400 rpm, and as it heats up i think the problem gets worse.  also if you sit there at idle and rev it up, the engine usually cuts out around 4k rpm or lower, it wont let it rev up to redline.
my car has a conical air filter, a straight exhaust, new ignition coil, spark plugs, spark plug wires, dit. rotor, dist. cap, and fuel filter.  I cant think of anything except that maybe it is starving for fuel.  I am hoping to change the injectors, fuel pump, and fuel pressure regulator with some off a junked 240 soon to see if that helps.  Are there any sensors I should be checking out?
my dad said to check the TPS...
my friend said the oxygen sensor...
but sensors are expensive, so if anyone could help me out?

[Nismos14]

i'd think o2 sensor but thats just me.....

[my240likenoother]

move the wire harnes comeing over your fuel rail see if that cuts it out
and ceck the fuel filter and the pump


edit: this should be move to tech

[tkrolo]

My 240 has a miss at around 4500.  It has been throwing a code for the 02 sensor, but just replaced that.  After reading my Chilton's thoroghly, it says that low fuel pressure can cause a number of codes and other misleading malfunctions.  I plan on testing my fuel pressure this weekend and expect to fix it by replacing the fuel pump with a walbro 255lb/hr pump.
Hope this helps.

[andrave]

mine almost feels like it hits a rev limiter when this happens...
ill look into the o2 sensor; any idea how much that will cost?
also, I dont have a fuel pressure gauge to test the pressure with, but I know it is supposed to be 33 psi after the regulator.  if it isnt, you are supposed to change the regulator first, then the fuel pump.  Im hoping to pick up both of those parts used before I go back to school.  
also, where is the 02 sensor at?
and how do i check the codes?

[halyoder]

aheck your mafs. if you have a maual on your car it will tell you that when a mafs is bad your car will not rev past 2800rpm but your car is still drivable. thats what was wrong with my sr20det so i got a new one and my car runs great.

[andrave]

alright i checked my chiltons and followed to diagnostic procedure with the computer in the pass. kick panel, and it looks like mine oxygen sensor is bad.  I'm putting a new one in tonight, I didn't know they needed to be changed every 30k.
I hope to god its not a mafs, I havent seen those cheap.  If I can find a 240 in a junkyard im just gonna rob the damn thing and keep some spares around.  
hopefully this oxygen sensor will fix things, if not then I'm in bigger trouble, and I'll have to check the fuel pressure asap.
how would I know if the mafs was bad or not?

[my240likenoother]

take the mafs off and check out the black box on the bottem make shure its not coroded or cracked if its good that look inside the mafs and there is a small hole in thebottem look inside that hole and if you dont see a small wire like peice going vertacly that thats your prob

[andrave]

ok i crimped a new o2 on it today and it seems to be running much, much better, you can stomp it and it goes.
it still misses once in a while, but its always had its little quirks.
thanks for the suggestion guys; it really helped.