Been driving around for the last couple of years without a Check Engine Light. It came on while driving. Although the car seems to be running fine, the check engine light would flicker randomly. I imagine a check engine light would stay on until cleared. I checked for codes and got 12 - Throttle Sensor (TPS) Full Range - Fixed at 20% open and 33 - Solenoid, Port Air Valve. Then I disconnected the battery for a good minute and went for a drive. Sure enough, Check Engine Light came on, would flicker randomly, and car ran well at low speeds. I have a few questions. Is the random flickering Check Engine Light normal; possible connection issue? Are codes 12 and 33 somehow related? One issue could be causing the other? Which one should I fix first. Any help is appreciated.