this will help with the turbo oil return leak
http://www.peachparts.com/Wikka/OM617TurboDrainTube

you can bypass your over boost protection (the black box on the fire wall) mines been bypassed for over a decade now... but even if you want to keep it in the loop try bypassing it as part of your trouble shooting.

the black box is just a valve, on or off. so its not going to matter if the lines are on backward... but if the valve is stuck closed, that may be a problem.

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