Check engine light comes on, engine runs rough
I unhooked the breather tube from the valve cover, unhooked spark plugs covers, took out valve cover bolts, but had an issue with one at the bottom middle above the heat shield... there is a part of the shield that is on top of that bolt (like an upside down 10mm bolt attached to the valve cover bolt below it) and I couldn't get it off.
I'm a novice, chickened out, put the bolts back on, spark plug covers back on, breather tube back on... the car runs/idles awful and the check engine light came on.
Any thoughts? Bolts are on gently, maybe not enough torque (no torque wrench). Maybe I don't have a spark plug cover on completely?