Diagnostic trouble codes

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Mar 25, 2005 | 09:32 PM

plumb-evil

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Joined: Mar 2005

Posts: 60

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From: Vermont

Diagnostic trouble codes

Hey guys hows it going? Im looking into getting a boost relief valve for my 95 power stroke. I have a 1705 super chips 3" down pipe luk clutch and flywheel, 4.10 5 spd denis at itp said that they have not tested the valve on a 95 and are not sure that I need it. The truck lays down at 24 psi but no ses light I did find some trouble codes:
PO107 Manifold abs pres/baro circuit low input
PO478 Exhaust pres ctrl valve high input
PO476 Exhaust pres ctrl valve range/perf
Any of you guys know what this means?
Going to do ccv mod, 6637 filter mod, And 5" straight pipes this weekend, any help or info greatly appreciated
Thanks Casey

Mar 25, 2005 | 10:18 PM

Ggg6

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Joined: Apr 2003

Posts: 424

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From: Northern IL

Yes the ECM will defuel at about 22-24 psi boost on all OBS trucks, I believe this goes for all 7.3PSD engines. I used a regular air compressor regulator set at 20psi. Plumbed into the MAP sensor line.

Mar 26, 2005 | 01:47 AM

cookie88

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Joined: May 2001

Posts: 13,653

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From: Cabot, Arkansas

Quote:

PO107 Manifold abs pres/baro circuit low input

On the 99+ trucks that would indicate a bad barometer, and would meccessate the replacement of the PCM. Since it also mentioned the MAP sensor when you pulled the codes I can only assume that the baro is seperate and (hopefully) independently replaceable. One of the 94-97 guys will have to answer that.

The 476 and 478 codes are actual valve malfunctions not the sensor, so your EBPV butterfly may be stuck partially closed. It will be fairly easy to check since you'll already have the downpipe off, just unhook the actuator rod from the butterfly and see if it moves freely.