[Camarokid08731]

Ok i need help in a big way. My car seems to run fine and then it feels like a few cylanders die and it richens itself out. then itll idle like its got a monster cam in it and stalls. when it stalls it shoots fire out the exhaust and makes a huge backfire that sounds just like a gun shot. then ill let it sit and itll start up after it cools down a bit. sometimes itll just fix itself. wich is why i beleive it is a sensor of some sort. it also happens worse in the cold and rain. If i give it gas itll sputter backfire and stall. Please help here are the mods list
Ls1 with 90k on it
Stock 4l60e
Stock Gears
Flowtech Longtubes with catless flowtech y pipe.
Flowmaster Cat back
The 02 sensors are the stock ones out my stock manifolds and are delcos
I have a LS6 manifold
Im running TR6 plugs because im planning on spraying it down the road
Ported throtle body
MSD wires
Timing is at 26 degress total
Any advice is greatly apreciated