Will not start, code P1381

Code p1381 cylinder position sensor/noise, but right now I do not know because when I discovered the code I have changed the crankshaft sensor, balance shaft belt, the water pump looks new and timing belt is good, alternator is good starter is good everything was running fine, got a new battery and changed distributor and still had the code p1381 since then. But when It runs it starts on the second try and third try and when it runs it runs fine and everything, but when pressing the gas just little like the rpm arrow gets so close to the zero and acts up just a little and my exhaust or pipe sounds shaky like its gonna shut off. This is just occasional because when I start the car any other time it runs fine and great even before I knew the code and the car also jerks the car bad after every shift and it is annoying, but that is when it gets shaky like I explained. Also, I did not mention about the MPH arrow also acts up that it gets stuck on twenty MPH and rpm is good but, any other time it turns on it runs fine and great and shift gears fine. Then two days ago while I was driving it just randomly shuts off and now it only cranks but wont start. A guy told me maybe it has to do with a cylinder problem or could be the ECM/PCM and suggest to get a new distributor because it might have worn the sensor out in the distributor. Please help