some guy hit my passenger side a couple weeks ago.and after it got fixed i've been getting 200miles per a tank

before i was averaging 300, right before the light comes on...

is this a problem with a leaky fuel line? or maybe because the 4wd is kicking in more often in the snow. or maybe its my ecu in 'rich' mode or w/e it is

anybody have solutions to the problem before i call the place that fixed my car up