[jwahl]

I have a '10 335xi with an AE performance cat-back exhaust and the Cobb 'Stg1 ST Drive' map. 'm getting code P03FF. After searching the forums, I've found:

P30ff pre-control boost control, boost pressure to leak from pressure line; error on loader 2

The consensus seems to be to check the wastegates, FMIC piping, etc. All of those items appear to be ok, and I took the car to local shop here in LA - they were also unable to find anything. They spent quite a while poking around.

I can consistently get the check engine light to come on by going wide open in 2nd gear around 5k RPM. There's no audible wastegate rattle and no obvious letup in power before it throws a code. It doesn't 'feel' like there's a leak.

Any thoughts as to what i might try next?

[Jeff@TopGearSolutions]

Visually things may appear ok but a small crack or hole is not always easily seen. Also as boost pressure increases parts flex and open up. That is why pressurizing the system to at least 15-20 PSI is the best method. Many times we see people do a "smoke test" which do not pressurize the system so it's not a bullet proof system in checking for leaks.

There is really only one definitive way of finding a boost leak on the charge side of the engine and that is by rigging up an air line to the hot side of the intercooler and pressurizing the system to 15-20 psi and checking for leaks.

That will find any leaks from the intercooler all the way up to the throttle body.

http://www.e90post.com/forums/showth...oost+leak+test

Common culprits could be any of the loowing and not limited to:

- Vacuum Lines (several under engine cover to turbos and to charge pipe and intake manifold)
- Boost Tubes
- Boost Solenoids
- Wastegates
- Turbo's
- Connection at intercooler
- Connection at throttle body
- Diverter valves or blow off valves

[jwahl]

very helpful. thanks for the direction...

As a side note, I went back to the stock ECU map last night to see if it would make a difference. It did not - still getting the same code consistently.