Where are the spark plugs located on a 1997 Cadillac Catera?
there is two bolts on the intake manifold to the bundle of wires on the drivers side take them out and there is a plug in front of the wires and one on the side unplug them move the wires to the side and you should be able to get to the spark plugs a lot easier than taking the manifold off. on mine had to change valve cover gaskets its a little bit of a job.
The spark plugs are under the intake manifold aka upper plenum ,in the center of the valve cover gaskets , on a 1997 Catera. Unplug the hoses and electrical wire clip/connections (you may want to mark the 4 hoses in the back for reattachment at removal), unbolt the intake manifold or aka upper plenum , you will then see the wires that go into the center of the valve covers , pull the plug boot…
it could be bad spark plugs, corroded, worn, old, dirty, or could be the spark plugs wires, old, damaged, loose, or in the last case bad coil packs or bad ecm, you can diagnose it with a scanner OBD2 and get the code, to research for especific misfiring code related to your problem to pimpoint exactly the cause of the misfire. ha ha ha reddragon