[polaris6933]

Hi guys! E92 with the N53 engine here. The car exhibits a rough idle (not limited to cold start) and on 2 separate occasions I got a check engine light while driving accompanied by reduced power. Those events were quite a part from each other in terms of time. Both times problem resolved itself. Coils and plugs have been changed and this helped somewhat with the idle. Also, a vacuum test was done and no leaks were found.

I read the error codes and I'm consistently getting 2AAF - Fuel pump plausibility (the low pressure pump, that is) and 2B49 which I wasn't able to find much info on online but it relates to the fuel mixture. After the second time I experienced the loss of power I also got 29F1 - Fuel pressure, plausibility. Obviously something's not okay with the fuel pressure so I'm asking what you recommend as next steps - I know that there are sensors which read the pressure and I've seen people recommend changing them but I'm wondering if it's worth the hassle and if I'm not better off just changing the pump itself considering the symptoms I'm getting.

2 additional questions - Firstly, do I need to replace the entire pump assembly, if it's at fault, or could it be diagnosed in a more fine manner? Secondly, do I risk ruining the HPFP if I run the car with reduced fuel pressure?

[crashoverride]

Just some generics as this doesn't directly answer your question and I'm more familiar with the N52
But the fuel filter is part of the pump assembly inside the gas tank under rear passenger seat and needs a special tool to remove.
I'm looking at replacing the pump filter and even fuel injectors on my N52 to pre-empt issues on my 200k N52.

You might have a dirty fuel filter?

[0l0dom0l0]

The fuel pressure plausibility fault can be caused by a faulty fuel pressure sensor. The low pressure sensor is accessible if you remove the throttle body. It sits by the HPFP. I would start by replacing that.

Faults relating to the HPFP are most likely a failing HPFP though.