Need help with code P0234
 

Been having my 05 SuperDuty with approx. 79,500 miles going into Limp Home Mode when pulling a load. Took it to a well respected diesel mechanic and he showed me where the differences in my water and oil temps were to much. He did a EGR delete, coolant flush and a new oil cooler. He also recommended i get something to monitor everything, so I purchased an Edge Evolution CS. Today, while pulling a small load up and extended grade the truck went into Limp Home Mode again..http://www.powerstroke.org/forum/images/smilies/mad.gif. My edge showed the code P0234 which I've learned is Turbo Overboost. My ECT was about 185 deg and my EOT was 193 dwg. Is this a problem with my turbo?

Any help is greatly appreciated.
Thanks.

Sounds like you need to pull the turbo and clean it.
DTS Articles - Turbocharger Reconditioning
the exhaust side of the turbo there is a ring, which they call the unsion ring, its what controls the boost of the turbo i'm pretty sure. and alot of them have the tendency to rust and stick. so i'm guessing that what they do is cycle the solenoid, because if you unplug the vgt solenoid on the turbo which controls the ring, it will sound the same when it cuts out on idle.
Here is a good Youtube one how the clean.
P0299 lack of power and turbo sticking on a 6.0 Powerstroke F250 diesel - YouTube
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Maybe that's an added code with the new flash but I've never seen it with a 6.0 and it's not in the 6.0 bible. It's a very strange code for a 6.0.

Check here (overboost condition)
http://www.dieseltalk.com/support/DTC.pdf
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P0234 introduced in 2009 in TSB 09-24-3.