Hi, I'm new to this and have some problems

[99exploder99]

My 99 ex, V6 ohv has been setting dtc's for engine misfire and lean O2 readings on both banks. The original problem was a misfire on cyl. #4 and then all injectors were replaced. It ran great for a day then it started again and worse. Please help. Todd

 

[boominXplorer]

how many miles? How many on plugs and wires?

 

[99exploder99]

it has about 110,000 miles on it and about 3,000 on new plugs and wires

 

[99exploder99]

I have codes P0304, P0306 which are my 4 & 6 misses and I have P0171, P0174 which are my sys. too lean on bank 1 & 2 and P1127 which is HO2S downstream but that code went away