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Latest Customer Reviews
Jet Performance Programmer Reviews
4.2 GAME CHANGER
Reviewed By Linda R (Titus, AL) Reviewed for a
2008Chevy 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.
Reviewed By David P (Aurora, IL) Reviewed for a
2007Chevy Trailblazer—12/14/2011 11:58 AM
I used the express performance tune. It installs quickly and I do notice a harded shift into 2nd gear and more power. It hasn't helped me with fuel economy. I will try the 87 octane tune when I go on a long trip