2001 3.4 no power, what now?

just bought this truck, told me it was the o2sensors that were causing the power issue. put the denso o2 on the upper and the urd o2 simulator on the lower, the urd help a little bit, but still not running like a 3.4 should. i cleared the codes also, no current codes are coming up but still plugging like a 22r. its got a k&n intake, im thinking that might have something to do with it, if it fucked with the ecu in some way.cleaned the maf, ign wires still good, no jumping, they are a little looser than i think they should be, but i tried to tighten the prongs up a little. idle is alright. when i give it gas, it just struggles to get going, and the intake still sounds like its pulling way to much air in. the passenger side injectors sound all the same, i put a tethascope on them, and the front injector on the driver side sounds good also, cant get underneath the manifold for the other too, so dont know how there going. i was gonna clean all the injectors this weekend, but just seeing what ideas anyone has before i start rippen her apart. should i try a stock intake? i traded my perfectly good colorado for this, its just frustrating, i want my truck to be up to speed, cant handle this slow shit haha.