Why is my car sputtering/lagging/lurching/driving me insane?

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My car has many issues. I'll try to put them in the order they began (more or less). It's possible it's caused by more than one thing. We've replaced the idle air control valve, the maf, spark plugs and wires, throttle position sensor, exhaust, air filter, alternator and battery within recent years/months. Doesn't matter what temp it is outside, although it seems worse when it rains or is windy. 1) Car lags/jerks during acceleration and sometimes while at a fairly consistent speed, usually between 60-70. Can happen at nearly any speed though. This has happened for 4+ years now; basically the whole time I've owned the car. 2) Code often says transmission component issue, yet if I manually shift everything is smooth and I have no problems shifting to park or reverse either. This has also displayed for several years. 3) Car has somewhat recently decided it doesn't like making multiple stops (within past 6 months primarily). I'll drive to a few stores and find that, after a couple stops, my car doesn't want to start. It turns over and sometimes catches, but then sputters out. When this happens, even when it manages to catch and hold, it will sometimes die or lurch/lag badly when I push on the gas to go forward. It has misfired during this time as well a few times, and the check engine light has blinked. This will also sometimes happen if I idle for longer periods of time. I will put it in drive and then when I push the gas, it will sputter and lurch or die out. As you can see, we've replaced quite a few of the usual suspects. With 240,000 miles, I'm don't want to keep throwing in parts without more certainty. Thank you!