99 V70 hesitation/misfire at startup

[MrWrongsneighborhood]

Hi folks
Kind of a newbie to this site
I recently purchased 150,000 mile V70
Extremely clean car with a hard to start issue after having valve job and head done.
Codes:P1081 P0350 P0354 P0355 P0336 and one for camshaft sensor
Changed plugs, cam sensor, crank sensor and a couple of coils
Still was hard to start but ran great after it started.

A few days ago, the weather finally turned and we started getting some warm days

Car got easier to start, but now has a hesitation for the first mile or so of driving.
Smells like it’s running rich and a couple times flashed the check engine light
Car will run very well after the first few miles
Yesterday, I drove it 230 miles and ran fine until I shut it down to go into an inconvenience store.
Came back out and started the car
Car was sputtering again.
Again it cleared up and drove fine until I shut it off.

Symptoms:
Running rich and stumbling at hot or cold start
CEL on
Still throwing P0336 and misfire codes
No ETS light
Will not rev over about 3500 rpm (sounds like it’s banging against rev limiter)
Occasional erratic idle

Any ideas?

[WhatAmIDoing]

Some of this sounds like symptoms of a bad ECT (engine coolant temp sensor). I would search the forum and follow the procedure outlined for testing (which I'm doing right now).