Help! Left oil cap off, oil splattered about on the top valve cover, now p0351,2,3,4 ignition fault

How much oil did you lose? Have you cleaned it all up yet? If so, what codes came back after you did that?

 

The oil is probably in the spark plug holes and shorting out the coils.
You can remove the windshield wiper assembly, clean everything off best you can.
Then carefully remove the coils. If the spark plug holes are full of oil, try to sucktion as
much oil out as possible before removing the spark plugs. You can spray carb clean all around
the hole, then start the car and allow the engine to attempt to start. This will blow out the oil/carb cleaner.
Only let it turn over for 2 or 3 seconds.
Clean up the plugs and coils, and electrical connectors, then re-assemble.

Hopefully, that is all you'll need to do.
Clear the codes, then start the car....

 

One trick I did, with an engine with sparkplug wells prone to accumulate stuff, was take an old, compatible plug, hacksaw just the thread portion off it, and glue that to a length of of hardwood dowel. After blowing out the well best I could, I'd gently remove the plug, then screw this gizmo in a few turns. Yeah there's still an obstruction in there, but sub'ing a skinny dowel for the wider shoulder of the sparkplug helped a lot: for spraying with say brake cleaner or compressed air.

 

Lay a towel across the spark plug holes when you go to do the cranking business and it'll blow all of the carb spray and all of that right into the towel instead of all over your engine and hood if that matters to you A Shop-Vac is your friend if you have such a thing the little bit of oil and vapor and whatnot that you're picking up if there's some sawdust in the shop vac it'll absorb it right up no problem.

 

Lay a towel across the spark plug holes when you go to do the cranking business and it'll blow all of the carb spray and all of that right into the towel instead of all over your engine and hood if that matters to you A Shop-Vac is your friend if you have such a thing the little bit of oil and vapor and whatnot that you're picking up if there's some sawdust in the shop vac it'll absorb it right up no problem.

 

Clean it up as asrdogman suggests. That should clear the P0351-4 errors. The P3190 is a redundant "yo, your engine didn't start" which will also go away once the coils are clean enough to start the engine.

 

It's not actually starting. When a Prius cranks to start, it goes at a much higher RPM than a regular car. This is often confused with actually running and then shutting down, but it's never actually catching.

You only get so many attempts at that before the hybrid battery is depleted, which is a real PITA to get out from under.

Be very careful with mail-order ignition parts. Amazon and eBay in particular are flooded with low grade counterfeits. Best to get that stuff from a brick-and-mortar Denso distributor if at all able.

 

There was no ignition problem prior to leaving oil filler cap off, everything looked clean in the spark plug wells; don’t see how it could be the coils. Definitely hang onto the old ones.

 

I might check the ecm connectors

 

Maybe flogging a dead horse.

 

maintenance mode?

how-to-engage-maintenance-mode-on-the-g3-prius.146916

 

It has to start first

 

congrats!

 

Just for giggles try the old coils again?