97 grand am 2.4 quad 4 missing

My daughter in law limped home a while back. The exhaust pipe got so hot it sagged and twisted(red hot I guess) We pulled the cat converter off and poked it out it was all wadding up in the pipes. The car is missing on the two middle cylinders I think it was. It has compression on all cyls, and spark on all cyls.Codes were 1411 ,and one that said low voltage to cam pos sensor, and one that said multiple cyl mis fire. I put a cam pos. sensor in with no change.Any ideas?

:) ok how you kno its missing on those 2 cyls? most likely its bad coil paks in the IDCover go to wrecker and find another to swap make sure its from a 2.4L tho b/c some vary in resistance, also try unpluging the cam sensor or use a voltage meter to see if you have power to those wires it could have very well melted a wire next to the exhaust manifold.... i would pull your o2 sensor out and have a look at the color on it. if its white you may be dealing with a head gasket issue, hopfully its brownish, only way i can think of a "cat" do that is running far too lean like leaking injectors?gas leaking into exhaust and fried the "cat" i would get a noid light and see if your have injector pulse.