Hello I just traded a Chevy Lumina for a 95 GMC Yukon 4x4.It runs really well,I have had the truck for a week and put some money into.It first started stalling at start up so I changed IAC,fuel pressure regulator,I changed the erg valve because it was plugged.Today I decided to check distributor cap and took off all the wires and forgot which one was which so I looked up the firing order and put everything back in place and it started misfiring but the wires where correct.So the last time I tried to start it it made a loud pop and the pcv valve popped out of the valve cover,and the valve gasket popped out of the valve cover so my wife said just leave it alone.So I had it towed to the shop today I just hope it is nothing bad can you guys maybe tell what you think happen.Thanks!!