engine rattles/slow acceleration on 2000 Chevrolet Camaro

For the past few days, I hear a rattling noise in my engine for about the 1st 15-20 minutes, then it goes away. While the rattling occurs, acceleration is much slower, and I even feel a little hesitation while trying to accelerate. When the rattling stops, I'm able to accelerate as usual. FYI - I had a gasket replaced and an oil change last week. Anyone that can help, thank you in advance!

Asked by for the 2000 Chevrolet Camaro
The early morning rattling is more than likely cause by a weak lifter. Once the oil pressure gets up and the lifter gets "Re-primed" the play or slack goes away and the push rod stops tapping.
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Sounds like a possible misfire, but hard to say without seeing it first hand. My recommendation is to take it back to the shop that did the work as this may be related.