Part throttle shake/ cold start miss, done everything

My car is a 13’ Prius , currently whenever I’m at around 10% throttle to maintain speeds on flat ground is just starts to shake. Zero misfires when warmed up fully.

On cold start I get a po304 and it always just pending. What’s weird is untill I drive it 10+ minutes it’ll throw misfire whenever I let off the gas . And you can hear the car make a stumbling decel noise. Not a consistent decel noise.

this all started when I got bad gas. Since then I’ve done the following:

new egr valve
New plugs
Remann injectors
Re cleaned egr system (wasn’t clogged anyways)
Removed all old fuel by removing pump and sucking it out with car tilted to drivers side
Tested fuel pressure (in spec running)

I’ve since put close to 1500 miles and ran plenty of 91 octane fuel to flush it out. Problems on cold start have improved but not gone away. Part throttle stumbling has stayed the same

engine is new short block from Toyota with 20k miles on it. I used all new oem gaskets and engine has ran trouble free up until this point.

I’m out of options. I could try the reflash for the egr but why would bad gas all the sudden require an egr reflash.

thought about fuel pump but car runs perfect above 1/4 throttle or so. Also my intake manifold is the latest revision listed in the tsb.

Car burns zero coolant and oil. Hasn’t lost a drop since I put the engine in.

any ideas?

 

Figured it out, rocker arm fell off intake valve .