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Hey fellas, for the last few days my ‘06 f250 has been running like it’s dragging a Silverado sideways behind it. Lots of boost, no power, and when I let off the throttle it sounds like blow gun on a air hose with the lever being pushed rapidly. The only code it’s throwing is a P0478. Any known likely issues, and or what I should start looking at?
Thanks guys
P0478:
Stuck Turbo, bad EBP sensor, slow responding (bad) VGT sensor, stuck VGT valve, or (very low possibility) bad PCM.
This code is set when EP_G is higher than EP_DES by 260 kPa or 37.7 psi for greater than 30 seconds.
That all depends on what equipment you have. What are you using for a scan tool? Do you have anything that can command the VGT actuator? The full version of ForScan can do that I believe. Certainly Ford's IDS system can.
Why not start by seeing if the EBP sensor is working?
Compare EBP, MAP, and BARO at KOEO. They should all be close to each other. Just bear in mind that some tuners (like SCT) don't read EBP accurately. ScanGaugeII, Torque Pro, and ForScan can all read EBP accurately.
You can also pull the EBP sensor and see if the tube to the exhaust manifold is plugged, as well as check to see if the sensor itself is plugged up.
Just for good measure, I would also make sure that the MAP sensor nipple on the intake manifold was not plugged up.
Ok so I’ve had to deal with a couple deaths in the family and I haven’t had a chance to mess with the truck until last night. The ebp sensor and tube were both very plugged up. I will check the MAP port/nipple today and then I’ll work on getting those test results for the vgt cycle.
Something I didn’t mention since I didn’t know where the MAP sensor was located, I noticed the problem my truck is having, started the day after I replaced the blower motor. I’m wondering if maybe I disconnected the MAP sensor or the tube?
