BMW Questions? Ask a BMW Repair Expert for Answers.
Hello, my name is ***** ***** I am a professional here at Just Answer. I have noticed that your question was not getting a response and thought I would see if you still need help with this.I apologize for the delay and I hope I can still assist you with this here.The problem sound like you may not have the timing chain aligned properly if you are getting valve train noise but I would start first with having the computer system scanned to see if there are any fault codes setting. If you can get this done and post back with the results we can work from there to determine the cause.
If your not setting any fault codes and you did not have this problem then I would double check your cam timing.
Okay assuming the cam timing is okay then If its bogging down with no codes setting then the next step would be to perform a fuel pressure test and see if the pressure holds when it bogs down.
Im not finding a code P173B are you sure its not a P0173 ?
The only code that would come close is the P0173 which is a lean code. Did you ever check you fuel pressure and are you sure the MAF sensor intake hose is sealing?
Well I am not sure how to advise you at this point, if you would like I can relist the question for you and see if someone else has something new to offer.