I put ford racing cams in my 07 GT in May ran great for a couple weeks. Than take it for a ride and started missing, engine light comes on and shows p0016. So I pull the valve covers and check the marks I put on the chains and sprockets to see if the chains jumped because that's one of the codes and it looks like they did.So I pulled the the front cover and reset the timing that didn't need it . Everything was in time. So I went ahead and ordered new phasers and put everything back together and no more code. I think factory phasers don't like racing cams and racing tunes.