Hey Scotty 😀 I gotta 2003 grand Marquis and i just put a new manifold in it and a few days later half the cylinders started misfiring but I know the spark plugs and coil packs are working so what do you think it could be
Check all vacuum lines going into the manifold as well as the manifold gasket. If it's a plastic manifold make sure it hasn't cracked somewhere.
i just put a new manifold in it
what manifold? intake? exhaust? turbo? oil?
a few days later half the cylinders started misfiring
which cylinders? how do you know? what trouble codes do you have?
t I know the spark plugs and coil packs are working
How do you know? did you visually confirm?
Misfire doesn't mean ignition problem. ANYTHING that interferes with combustion can cause misfire.
This is covered in our "Frequently Asked Questions (FAQ)". You should always check there first.
