lt4 fd

Today I floored it in 2nd gear at about 1500-1700 rpm and it popped loudly from either where my gutted cat is or under the hood and didnt accelerate and I let off immediately. I also noticed sometimes at below 2000 it hesitates to go like it will accelerate some and then kick in about a half second later, I dont know if its the opti doing this but I know mine is bad and it usually just lurches and bucks. Seems to be more prominant now that I put different oil and filter in but I think if it was an oiling prolblem that kept the engine from accelerating I would have serious and very noticable problems. Anything here that sounds bad or a problem you know the solution too?

Gripenfelter

Check for leaks in the EGR system.

Vacuum lines and EGR pump.

lt4 fd

Isnt that all behind the engine? Didnt know the egr could cause all that. Ill check it out.