[Biturbos4] Help with a few fault codes

[Steven Lin]

Quincy Chiang writes:

> Engine
> 17965 - Charge Pressure Control: Positive Deviation
>         P1557 - 35 - 10 --- Intermittent

>From the research I did, there are many possible causes.  You should
probably do a visual inspection of the TBB, BPVs, and IC hoses.  It
seems that tears in the TBB or IC hoses can cause this DTC, as well as
a stuck BPV.  A pressure-test of the intake can help find leaks.
There are instructions on audiworld.com to build one from Home Depot
parts, or you can buy the kit from awe-tuning.com.

A bad N75 valve or stuck turbo wastegate were also mentioned as
possible causes.  Even a bad MAF has been blamed.

Good luck.

-- 
Steven