Hello I have a 2004 350z and have been having issues with hesitation at full throttle. I’ve changed spark plugs, coil packs, cats, fuel pump, cleaned the maf, fuel treatment and seafomed through the throttle. At start up the exhaust sounds funky ( almost like a Subaru rumble) and under load. I can’t seem to figure it out so anyone who has had the same issue feel free to fill me in on any details/ give me advice. Thank you!

 

go see if you have any pending codes

 

Have you solved it, I've changed coil packs, injectors, valve cover and gaskets, plugs, and checked for vacuum leaks. I feel like something's off with my A/F Ratio, but can't really tell