2000 f350 lack of power/low boost

[00pwrstrke]

i recently bought a 2000 f350. it has a bully dog 6 pos switch in it and bank six gun that im assuming is only being used for the boost/egt. it also has a banks exhaust brake a bigger garrett turbo. ive noticed driving it on the stock setting and all the other settings but the two highest ones the boost wont go past like 10psi and the power just isnt there.when i turn the chip on high it boosts right up to around 26-27 no problem and takes off like hitting a nos button. any ideas why it wont build boost on lower settings? the air filter does look kind of dirty, i wouldnt think just that would turn the truck into such a turd??

[jermcd]

How many miles, any other mods?

[00pwrstrke]

136k miles only mods are the chip,intake,ehxhaust,turbo, and exhaust brake. 6 speed standard

[PowerStrokeBren]

Might have a boost leak check the intercooler tubes.

[Turbostang500]

Sounds to me like the chip is the culprit.

[kaya@bernhausen]

^^i'd have to agree. the problem is intermittent, so that rules out a leak. usually an aftermarket chip or tuner is the first place you want to look

[00pwrstrke]

I unhooked the bullydog chip today and seen like 14-15psi of boost under hard acceleration so it was better. What should it be? I hooked the chip back up and put it on low setting and it was back down to like 9-10 and felt alot slower. Turned the chip all the way up and boosted right up to about 25-27. The chip may be the problem. Have to save for a new ts chip and try that. Also the six gun appears to still be all hooked up to the sensors and everything could that be messing wit the other chip?

[PowerStrokeBren]

Disconnect the six gun that could be your problem,and you cant stack on a 7.3.

[00pwrstrke]

I unhooked the six gun with no change. The guy had been running the 6gun with the bullydog for a few years with no problems, maybe it's always been like this and the previous owner didnt care to improve it. Is it possible the bigger turbo with the bullydog chip with their tunes for stock trucks is messing it up? I've seen that the turbo is capable of 27psi Witt the turn of the dial maybe I just need a custom burnt chip ?

[Turbostang500]

Your lower hp settings will push less fuel which will have a large affect on turbo drive pressure. Lower drive pressure will result in lower boost pressure. Sounds to me like you could benifit from a custom tune. A faulty sensor could be causing this also. Is the CEL on?