I would pull the fuse on the fuel pump, connect the pressure guage to the plug hole and crank the engine over once or twice. My gauge has a needle that records the high reading so I do not even have a remote starter like the old setups had. You will probably get a code of some sort, but it would go away when reconnected. Metal pieces that large would concern me, but probably not related to rings/valves (compression) IMO.
08 JK 23S - Colorado Jeep Club No. 204
Too much to list - see my profile for details on build
16 JK Rubi with all the trimmings
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"It takes a special kind of stupid to believe criminals will follow gun laws."
I do not consider myself a smartass. I point out the obvious, search for the truth, and speak fluent sarcasm. I am, by experience, an accomplished curmudgeon.