'96 2.4L engine idles good but sputters when I give it gas.

(Hi. I did look around before I posted this, but I wasn't able to find anything).

I have a1996 Toyota Tacoma 2wd, 5sp, 2.4L, w/202,544miles on it, standard cab and to the best of my knowledge the only thing that's ever been done is the usual oil change, tune up, etc. I picked this up from a friend and when he bought it 5-6 yrs ago the check engine light was always on but it ran great so he just ignored it. when I got it a couple months ago the check engine light was still on but it ran great and didn't show any codes. so about a week ago I was driving down the road and all of a sudden the check engine light went off and it started sputtering and had no power, it was all I could do fluttering the gas pedal and riding the shoulder of the road to make it another mile to my house. when I initially start it, it runs fine. but when I give it some gas it starts sputtering and backfiring. I thought it was the fuel filter, so I replace it and it didn't change a thing. Friday I was forced to drive it to work, the commute from hell. It ran like crap the whole time and spent most of my time on the shoulder of the road w/flashers on doing 10-15 mph. when I was leaving work I was just baffled how good it runs for the first 5-7 secs then starts missing when I give it gas. so on my way home I turned the motor off as I was coasting then started it dropped it in 3rd gear and gave her some gas. I started accelerating, but after 5-7 secs it started sputtering again. I turned it off again, started it, dropped it in 3rd, and mashed the pedal to the floor. once again it accelerated for 5-7 secs. when I got home I noticed that the check engine light was on and I checked for codes. I found 3 codes. 1) random misfire 2) #2 misfire 3) #4 misfire. I am not understanding why it runs good for a few secs after starting then goes back to sputtering. at this point it looks like I'll be walking 7 mile to work and hopefully get someone at work to bring me home and pick me up Tuesday morning.....etc., but I wont be able to do that for too long. At any rate, I thank you for reading my pathetic little story and even a point in the right direction would be greatly appreciated.

 

Fuel pump possibly.I had a 87 toyota xtracab 4x4 sr5 that did this it would idle fine if you tried to floor it on a hill it would crap out,it started getting worse at different throttle positions.the fuel pump had volume but not enough pressure. But it did not throw a check engine light. Possibly your throttle position sensor is loose or needs re-set.