turbo? Knock sensor? running lean?

[SideWinderGX]

im not an expert, but as far as i know, this is all close to correct:

knock is the preignition of gasses in a cylinder. instead of the piston compressing the gases and having the reaction occur, they combust prematurely, backfiring, and slow the pistons down. hence, they could slow the car down if bad enough. it happens if you ahve too high of an octane in your car, or if you mix them.

although, i dont think mixing gas matters as long as its the same octane. maybe it was a bad batch from one station that messed up yoru entire system.

um, if the blow off valve is leaking, thats obvoiusly not a good thing, although im not sure how that would relate to knock or anything messing up.