I HAVE A 2007 DODGE SPRINTER WITH CODE PO299 WHAT TEST CAN I DO

This code pertains to the turbo housing resonator which makes the turbo quiet. Normally, the part is broken into to 2 parts which are glued together. This is the source of the problem, the glue usually fails and this affects the turbo pressure which is usually needed in going uphill. The part can be bought from the dealer or check your after market supplier of this turbo model. On some European cars, this P0299 fault code can also mean that the waste gate solenoid actuator is defective. As such, it could cause turbo inactivity causing the engine to loose power. To check, test the wirings of the turbo waste gate solenoid and the vacuum supply to the actuator. If OK, the most common fix is to replace the waste gate solenoid.
Turbo Boost Pressure:
The way turbo boost pressure works, if the turbine housing has small apertures (passage ways), it will make the turbo work at lower engine speeds. However, it can cause restriction to the exhaust gasses flow at higher engine RPM. If the compressor assembly is too big in relation to the turbine, it could cause stalling, but if it is too small, it could cause turbo over-speeding and will self destruct. In this sort of set-up, the system is controlled by the engine management system. Boost is generated by increase of exhaust pressure that is NOT going into the engine. Usually, this boost pressure is detected by an air flow sensor when a signal is then sent to the ECU (engine computer) which regulates boost pressure.
NOTE: In order to ensure that a high boost pressure is developed even at low engine speeds, the turbine and compressor sizes would have to be made smaller as much as possible.
In order for the wastegate to work, the compressor reference port must be hooked up to the compressor side of the turbo because the vacuum line attachment limits the set spring pressure. This in essence, will build unlimited boost pressure until your engine is destroyed.


Hope this explains.


thanks

Check all hoses to and from turbo to intake .. it is most likely a leak somewhere and the pcm is reading it as a underboost code.