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.

 

I don't think the two are related. The port air solenoid has to do with your emissions stuff. It could be full of soot and need a good cleaning, if it hasn't been completely removed. The full range throttle sensor means the ECU isn't getting the correct signal from the full range sensor. The Series 5 had two sensors, a narrow range for idle and near idle throttle conditions, and the full range for everything beyond that. For some reason or another, it doesn't like the full range signal. Check out the tps testing procedure, and probe at the ECU as well to make sure a mouse or something hasn't chewed a wire.