I have a 95 940 turbo, 120,000 miles, with sluggish performance. Engine runs smooth but is very sluggish below 3,000 RPM. To maintain 55-65 MPH, trans has to shift down at the slightest hill.

I've had the turbo rebuilt 3 times with little change in performance. CAT is not plugged. I've replaced part of the rubber air intake system and inspected all the rest. Computer doesn't set any codes or turn on check engine light.

I suspect some turbo-related boost problem, but can't come up with an effective way to measure boost under actual driving conditions.

Any suggestions?

Thanks,
Ron Yates