Last couple of time I checked, my air restriction gauge has been half way down. I have been increasing when i change the air filter because of the gauge - the filter comes out not looking that dirty. My last couple of filter changes are down to 10,000 miles & I don't drive in dusty conditions. I have been using a Purolator air filter. I also installed a Quad XZT module about the same time.

My MPG dropped about 2 mpg in August (before winter fuel) and three things cross my mind:

• The filter itself is very restrictive causing the mpg drop & restriction gauge to come down.
• The restriction gauge itself is too loose coming down when filter isn't too restrictive
• The Quad XZT module pulls more air (more power due to XZT = more air??? or just more fuel), which on a given filter size results in a bigger pressure drop, pulling in the restriction gauge. Also, XZT could be responsible for MPG drop (no, my driving habits did not change - I got the module for the CLAIMED mpg increases)

 

those minders on the early cr trucks have not got a good spring in them. my first 03 would pull it down when new.

 

The module will also make you suck in more air when on the throttle hard, making the gauge suck in.

 

Wet air filters really mess up the guage too! Heavy rains and high humidity will cause the filter to get "heavier" and cause more restriction.