Random miss, no codes in computer

I have a 2002 3.0 Jaguar X-Type, 123K miles. Changed the plugs and all of the recommended gaskets using all Jag parts.

Immediately after the change, I suddenly have a random miss that only occurs when accelerating strongly at low RPM - like at 45MPH in 5th. It does not seem to miss at higher revs, or when giving it a lot of gas. A little less or more throttle and the miss goes away.

Sounds like it’s lean, but everything is torqued and tight. There are no codes coming up according to the nice folks at Autozone.

Any ideas about what I should be looking for?

I once had a similar situation and it turned out one of those new plugs had a cracked insulator on the wire connector end of the plug.

Was this crack obvious? How could you tell it was cracked?

Agree. I’d try another set of plugs first. Also, did the OP check the plug gaps and adjust as needed?

Yeah, it was obvious.
It was my first car ('76 l6 Nova) and maybe my second time changing plugs on a car.
It didn’t act up right away, so it probably started as a hairline crack.
When I pulled the wire boot off the ceramic was in two pieces, held together by the center conductor.

Yeah, I gapped them all, at the narrow end of the spec. Exactly how does a crack like this lead to the observed behavior, with a miss occurring only within a very narrow band? I’m dying to know!

High frequency electrical discharge is a very funny thing. It does not always behave the way you might expect it to. You describe the miss as happening when the engine is under the most strain. Maybe it is happening all of the time, but you can only feel it when the engine is pushed the most?