Thought it was just a fouled Plug... Engine running lean

[RubySlow]

Okay so Yesterday I went to go to work and When I went around the corner I could hear a thump, I thought spark plug, you could smell the unburned fuel in the exhaust.. SO I decided to put those champion iridium plugs and those taylors I have. Some plugs looked black and smelt relly gassy and some were white, So some are runnin lean and the others arent?
I just took the car for a test drive and no more thump or raw fuel from the exhaust.
But Now when you step on the gas the car loads up, like its not getting enough fuel, and pops in the exhaust so I know its lean.
She idles fine, tps works, a/c works, no check engine light... so Im thinkin fuel filter or something stuck in the rails, bad regulator? Injectors?

 

[RubySlow]

Would an O2 sensor or fouled cat make the computer run the fuel ratio lean?

 

[reserved50]

dirty mass air flow sensor?, if its that bad it'll throw an engine light sooner or later

 

[RubySlow]

bump