Reviewed By RICHARD J (Parachute, CO) Reviewed for a 2005 GMC Savana —7/13/2014 9:25 PM
Big difference in power. I get 3 to 4 mpg more when using performance level.
Reviewed By Linda R (Titus, AL) Reviewed for a 2008 Chevy Trailblazer —10/19/2017 4:11 PM
Jet seems to be the only programmer that works for the 4.2 chevy inline 6. No problem with the installation and I noticed an instant increase in the low end power. this is where the 4.2 really sucks. Don't know why they did not use the 4.3.