Yeah Big Joe but pulled these same passes before the mods without Surge. Vail pass is 10k+ but also had surge at less than 5K. Thought I was blowing a turbo so had it all checked out, since I'm 1000 miles from home. no codes, not damage in turbo, no play in shaft,except normal. So Surge or waste gate must be the culprit.
Well then.. could be W-gate, but I would take a real good look at yer I/C boots and intake boots as well. Clamps tight.. weathered.
If they're the Origonals.. They're 10 years old now.. with 120K on'm.. know what I'm say'n.
Joe