2011 W/ P0303 and P219A

198,000 miles, plugs and coils replaced ~160K, #3 injector replaced ~185K miles. Random P030Xs over the last few years.

Two days ago wife drove 45 miles, mostly interstate, got off, and pulled into a parking lot. Then the engine ran rough, CEL came on. Roughness increased and CEL began flashing. I met her and my code reader showed the P0303 fault and a 219A pending.

Drove Pri home today with the following symptoms:
1 normal acceleration but roughness when trying to hold speed, greater roughness starting to accelerate. CEL on and then flashing with the increased roughness.

2. Full acceleration felt smooth but same roughness trying to hold 65mph and starting to accelerating to 70+mph. Smooth coasting to a stop. CEL was off for minutes several times during the trip home, seemed better at the higher speeds than in the 45mph slowdowns

3. Swapping cars in the driveway, the Pri ran on battery only and had no CEL.

4. Checked codes again, no faults but a P0303 shown pending and as a historic fault (Torquelite).

I have never cleaned the EGR system so that is first on the list. Will check plugs, #3 injector, and do a compression check. What else?

Thanks