hey guys

so i installed my dynatech LT headers about 2 months ago and have had Bill from PHP edit my tunes but my mileage has gone to the gutter.

trust me i have kept my foot out of it so dont say that

i just did a cross state trip (300 miles) and averaged 13.5 mpg, granted some places were very windy but still 75% is relatively flat and not much wind

last summer i did it twice under basically same conditions but with stock headers and averaged around 17-18 mpg

whats going on here? everyone i hear from has benefitted mpg wise from LT's

 

something has to be wrong. I would call PHP and tell them whats up and see what they. Something with air/fuel flow is not correct. Converters, maybe? I know my blown out pre cat has cut my mileage down that much as well.

 

You maybe dealing with winterized gas as part of the drop in mpgs.
Contact PHP, there might be something else Bill needs to look at.

 

are your front o2s wired right? they could be bad. i saw my mileage after i did longtubes drop from 16-17 to 12-14 i replaced my front o2's and it shot up to 18-19 and 20-22 on the high way.

i recommend to everyone to do the front o2's when you do longtubes if you have 80,000 or more miles.

 

i only have 20k miles, i was gentle as i could be with them when installing them and have them installed right.

i will contact bill and see what he says

 

after my obx's mine dropped too, about 1mpg. with new front 02's. im not tuned yet, as a side note. im still rollin about 14-14.5mpg with this winter mix, and ran 15.5 or so with good summer gas. could have a lot to do with my new found heavy foot tho... but thats sounds like too much of a drop, id talk to bill about that