Kwokadoodled

Hey guys,

So i've had my 97 CL for about 6 months now. My CEL came on about a week ago: P0304 and P1399. I've brought the car in to my mechanic several times, and everytime it seems to be fixed, the P0304 code keeps on coming back. The P1399 code is new! Please help i dont know what the hell is wrong with the damn car! It's got a rough idle and kinda sputters (popping noise from the exhaust)..Its pissing me off.
Ive already done new distributor, dist cap and rotor, spark plugs, spark plug wires, fuel filter, O2 sensors (front and back), radiator, map sensor, battery.
I still dont know what is wrong. I just got the car back from Acura and they said they need to do a few tests to find the problem cuz they cant even figure it out! but they want $500-600 for all the diagnostics and i dont want to dish te money out. They said it could be the head gasket that is leaking either coolant or oil into the combustion chambers..but there is no black, blue or fluffy white smoke coming out of the exhaust. EGR Valves maybe? Please help!! what else can cause the misfire codes? Thanks in advance for the replies! any help will be greatly appreciated!!

Kwokadoodled

Oh and i forgot, i did an engine flush, fuel injector and throttle body clean/flush as well..and i put some fuel system cleaner in my tank as well...i dont know if that changes anything tho? Thanks in advance!