Last week my wife's CRD had check engine light and P0299 underboost code. I found a mouse nest in the air box, replaced the filter, removed and inspected both CAC hoses and cleared the code. Now when babied all is fine, but driven normal to agressive it goes into limp mode and throws a P0234 overboost code. Anyone have any ideas on the possible causes of this code? It is still under warranty but we're out of town roght now and couldn't leave it at a dealer for days. Thanks in advance for any help, Tigafla

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'05 CRD Limited: 174k mi Euro Torque Converter, EHM, ORM, Racor fuel filter, Original Rocker Arms, Amsoil everywhere
'98 Dodge Ram 2500 Cummins 24 valve extended cab short bed
'01 Jinma 4wd diesel tractor

well if there was a problem with the vacuum line for the turbo "actuator" then it could cause the codes you described.

Here is where an accurate boost guage would be helpful, it would be nice to see what boost your actually getting so you could see if your boost is really off, or if its another problem. EG if your boost reading was fine from the aftermarket gauge, then you pulled up the boost reading via the OBDII port and saw it wasnt near there, you could look at your MAP sensor.

That being said how recently have you checked your MAP sensor? Maybe if it was plugged it might be reading off causing the codes to be thrown......thinking its overboosting and thinking its underboosting.

I know its something simple but I think that might be a good thing to check first off, if you havent already.

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http://www.Colorado4Wheel.com
"Its not about what you can DO with your Jeep, its about where you can GO with your Jeep."
Knowledgeable - But Caustic

Thanks Sir Sam, I blew off the map sensor with shop air, how is everybody cleaning thiers? Tigafila

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'05 CRD Limited: 174k mi Euro Torque Converter, EHM, ORM, Racor fuel filter, Original Rocker Arms, Amsoil everywhere
'98 Dodge Ram 2500 Cummins 24 valve extended cab short bed
'01 Jinma 4wd diesel tractor

Electric parts cleaner or MAF cleaner.

How dirty was yours? Like really gunked up with crap? or just kinda sooty?

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http://www.Colorado4Wheel.com
"Its not about what you can DO with your Jeep, its about where you can GO with your Jeep."
Knowledgeable - But Caustic

It was just a little sooty. Do you just clean the part that sticks out or do you have to clean up inside? Thanks, Tigafila

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'05 CRD Limited: 174k mi Euro Torque Converter, EHM, ORM, Racor fuel filter, Original Rocker Arms, Amsoil everywhere
'98 Dodge Ram 2500 Cummins 24 valve extended cab short bed
'01 Jinma 4wd diesel tractor

I just blasted it with the cleaner(all of it), though mine was just gunked up solid, sounds like yours wasnt bad.

Boost pressure test I think is next in order for you.

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http://www.Colorado4Wheel.com
"Its not about what you can DO with your Jeep, its about where you can GO with your Jeep."
Knowledgeable - But Caustic

I'll tee in a gauge as soon as I can, thanks again Sir Sam. Tigafila

_________________
'05 CRD Limited: 174k mi Euro Torque Converter, EHM, ORM, Racor fuel filter, Original Rocker Arms, Amsoil everywhere
'98 Dodge Ram 2500 Cummins 24 valve extended cab short bed
'01 Jinma 4wd diesel tractor