Don't know what to do anymore
 

Ok, I don't want to get rid of my g35 coupe; I love the car but I need some advise from people who know what they're talking about. Now the past couple months I've had some issues. Mods: plenum spacer, pop charger,z tube, full Borla exhaust one gutted cat cause I guess it was causing issues with my car.... Well I've had a couple bent valves and had to obviously get to the valves and replace them. Ok so they are all replaced and so is my crank pulley oil changed new belts as well....... Car is now throwing O2 sensor COde....... Has slight dip in Rpms. Ecu was reset which is better than before cause when I first turned it on before it would die sometimes at random ( drops really low and turns off ) now it has a slight knock again but it's faint and doesn't happen all the time. I honestly don't know what it is...... Don't know what to do...... I've fixed this car way to many times now I just baby it...... Should I sell it or does anyone have any ideas of what it could be? My
Buddy works at Nissan and we work on my car together.... The other cat isn't gutted.. He thinks I should sell it. I do not want to.... Idk someone please give me their opinion it will be greatly appreciated and thanks a lot.

Sell it. Car isn't worth nearly enough money for those headaches.

Buy someones used HFCs, if one OEM cat went bad don't you think the other side could be causing you issues? With both sides of your engine flowing correctly you may be able to clean/replace the sensor that's throwing the error code and be able to enjoy what you drive.
Gary

Thanks i know I need to gut the other cat... But yeah probably going to sell it. It's just constant issues now out of no where

Thanks for the fast replays guys I appreciate it.