Intermittent Stalling & check engine light comes on then goes off after few days

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Suzuki Reno 2006: it happens every so often, Pull up to a stop sign or red light and the engine with shut off. Need to turn the car back on a few times but it starts. When im driving, at a low mph pace, sometimes it will shift a little and the check engine light will come on and when i press the gas it won't accelerate pass 20 mph. Took it to mechanic and they couldn't find no codes, they clean'tthen , then changed the throttle body assembly, The cpu system module, and the hoses, floor petal and recalibrated the system. Things work for a short while but still same thing happens. Took to a wal-mart oil chance and the scan read first the codes read: P161B only MY neighbor also scanned it and the Second time the codes read: p0340,P2105, P0403,P2110,P2106 P1610 I took it to a another mechanic and they ran the scan tool and no codes came up, tested drive it and it ran fine! Whats going on? Please someone help me and assist if you know or have had similar experiences