had new plugs put in and not with in a couple of months plugs came loose ,had to bring truck to different shop to fix problem 2 of the 8 plugs had to be replaced and the rest had to be retighten down to fords specs the cost of this was 144.00 bucks!! went back to zappas and told them of issue and i wanted refund of the 144.00 iwas told no !i should of brought truck back to them ,now why would i do this when they couldnt do the job right the first time , i will never bring or remend this shop to anybody . the person i dealt with had an answer for all pretty much said to bad !!!!!