i recently did a tune up and ever since i suspect im running lean. i have a nordisko air fuel guage and have been using it for 2 years. and all of a suddened my light show disappered. at wot im 2or 3 bars down from what it used to be. tps is at .60 already . did anyone ever use a fuel regulator on a speed density? fuel filter just changed. any help would be appericated.

 

what about a iat resistor?