2005 Chevy Trailblazer inline 6 cyl. Gutless, accelerates like the putt putt cars at disneyland. In park or neutral, WOT gets 3500 RPM and no more. Runs smooth, not missing. I would say this has been coming on slowly, changed the plugs about three weeks ago due to my wifes complaint that it felt sluggish. Now it is terrible. Could this be a plugged catalytic converter? What else should I check, or since it has to be effecting emmisions just take it to the dealer for warantee? Is the "New GM" honoring emissions warrantees from the "old GM". Almost forgot...MIL is off and no codes are stored.