3sgte WOT prob Options

[19celica90]

well couple days ago my 3s started acting up, rough idle, hesitation and missing alot. So i checked the plugs and they looked worn so i replaced them along with then distributor cap and rotor. Now it idles fine. But, whenever the car is warmed up and out of the "safe mode" it kinda looses power. For example, when im driving 1st and 2nd are good, not affected, but my 3rd 4th and 5th the car sounds like its farting, like a prrrt prrrt prrt sound, lol best i could do. if i accelerate slowly and build boost slowy it doesnt do it at all. but say i wanna merge into traffic or take off and go wot it does the prrt thing. So i thought boost leak cuz its doing it under boost so it seems load based. checked out my piping, everything solid, not hissing from pipes or intercooler, havent done an actual boost leak test but i will soon. i did notice on my dp i had two hairline cracks. both right after the 1st o2 sensor, and im wondering if the 2nd sensor isnt seeing all the exhaust and maybe trying to compensate but i dunno. any feedback would be great guys, thanks