Long term lean running

[scrwright]

Getting the above code on my 03 9-5 aero. Also getting the boost being dropped over 2k revs with more than 1/2 throttle. Tech 2 is showing knock detection across all cylinders when it starts dropping the boost.
All intake pipes are new, as is brake vacuum pipe & servo. Not done much on turbo engines so what causes lean running on an engine running posative inlet pressure? Could it be the turbo overboosting? I would have thought the ecu would measure the MAP an fuel accordingly? Could it be a fueling (lack of) issue.

Engine is recently serviced with the correct aero plugs and always run on super.

Thanks

[Matt Cyclone]

DI pack on the way out? Or (like you said) it could be that the fuel pump can't keep up with demand...

Assuming that you don't have an air leak (ALL the pipework done, all the 6mm pipework from the APC to the turbo, EVAP system and wastegate, PCV#6 on the car?) then I would have thought that fuelling OR a knackered lambda sensor is the issue - if the lambda is reading bks then perhaps the ECU is thinking that the engine is running lean?

Never used Tech2 (lucky man!) but with the torque app I can log the 2 O2 sensor readings, so I imagine you can do the same?

[scrwright]

New DI and the same boost/chattering issue. Plus side is the lean running code has cleared since changing the brake servo. Off for a run out with the tech 2 plugged in to see whats going on now.

[scrwright]

Just fitted a new Maptune recirc valve and all whistling noise has gone, getting a little chatter noise at WOT & higher revs, is that normal or is my turbo still over boosting?