2018 Prius 3 engine vibration on decel and low throttle input

Just bought a decent gen 4 with 81k miles. Drives great for the most part. When you accelerate to speed and then take foot off the throttle 95% of the way and hover rpm just above where the ICE is on, the engine will vibrate if you hold it right above the transition zone. In ev mode and at higher acceleration it drives well.

I was thinking of cleaning intake manifold ports, egr pipe and egr valve and skipping the cooler (it looks like you have to move the inverter)

I also thought maybe spark plugs but AI said it’s most likely not spark plugs because it would show symptoms through the full rpm range and to try cleaning the egr system.

only posting because I saw on here that some people don’t have egr problems even at 300k

coolant was at the low line when I bought it, just topped it off and drove about 200 miles yesterday for the first time.

57 mpg average over the 200 miles.
Edit:

just saw another post where it’s doing the same thing. He replaced his egr valve at just 40k miles. Neither of my scan tools can detect if the egr valve is stuck open. So I need to buy a third smh

I’m going to buy all the gaskets and try cleaning EGR valve. It may be sticking from sitting around on the lot

 

@BiomedO1 this is my thread and I dont have any check engine codes or pending codes.

 

Thanks for taking the time to read and respond. I assumed the PID for stepper motor position would tell me whether the Valve was moving or stuck in one place. I was planning on getting the computer that allows you to actuate the valve while reading the position.

I will move forward with my plan to clean the Intake and passages this evening and take a look at the buildup in the EGR pipe and on the EGR Valve and report back.