[jokergerm]

So sometimes mainly in higher gears my n54 starts stummbling badly The check engine comes on and it says reduced power engine malufunction. All i do is restart it and its fine, as long as i dont get into the throttle alot

Does this sound like the HFPF? It does it so randomly its annoying. Other then that it runs fine and with my Jb4 on map 0 it never does it, but on map 2 it will from time to time

Iike today it was running fine, i did some 3rd gear pulls with no issues

I searched and someone else had the same issue but it was a vacuumn line. But mine comes and goes

Its a 07 335i coupe with jb4 dci 3" d
I need a E60 M5 already

[Tchao]

With no mods, same happened to me. Took it in the 2nd time it popped up and it was code 2A7C Dirty Intake Vanos Solenoid.

[Krazyjumpshot]

sounds like a vaccuum leak...try checking your hoses...it could be a small leak n its only noticable when u run a higher psi

[jokergerm]

Ok ill check tommorow

What would make it be random though? Sometimes its fine during wot pulls

[skyguy]

When I put in jb4 mine did that. It was the plugs.

[jokergerm]

Yea i have 78k on the oem plugs.
I will change them tommorow

Does this issue sound like the hpfp failing at all?

[jordan313]

sounds like misfires. change plugs then coils

[jokergerm]

i went to order my new plugs today and they will be here tommorow

On the way home i opened it up in 2nd gear and the half engine light came on for a second and the check engine light and then i let off and it went away

I really hope its not the HPFP but it may be

[tmo24]

Mine had a similar issue and the dealer replaced all 6 injectors.