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I'm struggling to find an answer to this issue on the forum-please direct me to a thread if I was unable to find it.

My car (2000 323i automatic with 99k miles) will randomly every couple weeks lose a cylinder and run on 5 making it very sluggish. If I put the car into the manual mode (steptronic) and run it pretty hard for a few miles it will start firing again. It seems to happen initially when slowing through turns. I was able to catch a couple of the codes: P1250 and a cylinder such as P0301 (the odd cylinders are usually the only ones to misfire).

I've replaced the entire cooling system in the last 3k miles.

I'd like to not have to drive like a bat out of hell all the time to keep the cylinders from misfiring and my wife isn't as much of a fan when a passenger.

any direction is helpful. I'm down to replacing the fuel filter and O2 sensors. Am I on the right track?
 

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Driving the engine hard will not clear misfires and is really the wrong way to attempt to address the problem.

You likely have vacuum leaks, fuel pressure/volume issue or secondary ignition issues.

You need to get the Freeze Frame data associated with your codes and post it up here for review and comment.

Also need to know what the Long Term Fuel Trim values are at warm idle and while cruising at a steady 40-50 MPH/

See the first few links below in my signature.
 

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I'm struggling to find an answer to this issue on the forum-please direct me to a thread if I was unable to find it.

My car (2000 323i automatic with 99k miles) will randomly every couple weeks lose a cylinder and run on 5 making it very sluggish. If I put the car into the manual mode (steptronic) and run it pretty hard for a few miles it will start firing again. It seems to happen initially when slowing through turns. I was able to catch a couple of the codes: P1250 and a cylinder such as P0301 (the odd cylinders are usually the only ones to misfire).

I've replaced the entire cooling system in the last 3k miles.

I'd like to not have to drive like a bat out of hell all the time to keep the cylinders from misfiring and my wife isn't as much of a fan when a passenger.

any direction is helpful. I'm down to replacing the fuel filter and O2 sensors. Am I on the right track?
P1250 is a false code, it does not translate into any BMW malfunction that I know of. P1nnn is a unique code for the automaker that has a car that generates such a code. P0nnn is a generic code and any car that cam make such a code will have the same problem -- that is, the error code will translate to the same thing. For example, you have P0301, this means MISFIRE CYLINDER 1. It always means misfire, cylinder 1, although the reasons for a BMW to misfire and the reasons for a Ford to misfire can be different, the code always means the same thing because it starts with P0. On the other hand, if a Ford and a BMW both made a P1250, the meaning would be different, or could be different, because since it's a P1 code, then the meaning is unique to the automaker of the vehicle that generated the code.

And, no, you are not on the right track.
 
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