06 BRM maual transmisssion cold run issue

The car has been running great in this extreme cold until last week. No codes with vcom. Air & fuel filter ok. After starting & placing in first gear it would pull no problem. Slight pedal would not bog it down. Now when I put the pedal down to move it in first gear its like its flat unless in push it down a little harder, does the same in 2nd gear until I have a little speed. Boost lines are good as are the vacuum lines. I am baffled. Thanks