Ford Repair: 2003 F 150 trouble code, gasket leaks, intake manifold gasket

Question
Yesterday, after the temperature dropped to below zero, my Service Engine Light came on.  I had replaced two oxygen sensors about a month ago. Took it in for a diagnostic and the codes were: p1131 and p1151.  The tech told me that I had a leaking upper intake manifold gasket, and the cost to replace (including isolator bolts) was going to be (in my opinion ridiculous) 677.00.  I work for an auto parts retailer and can get the gasket kit and replace at one of our shops much, much cheaper.
My question, could this be weather related? How safe is it to drive?

Thanks,

Paul

Answer
Hello Paul, Remember weather always plays somewhat of a factor on mechanical items. when the manifold gasket leaks it creates a vacuum leak and the engine will run lean and the PCM will adjust fuel to compensate for it causing possible less mpg and causing a cylinder to possibly run hotter than is should. Its not a severe concern but does need attention so it does'nt cost you more down the road. Hope this helps Thanks Tony