EGR valve

I recommend checking in there. No need to fuss with the spring, but do remove the rotor and look inside to see if the ski jump inside has a rut worn into it. Replace the valve if it does.

 

If you take it out do you have to put it back in a certain way?

 

If you find some of the older threads talking about it, you're good to go.

The screws holding the stator on can be stubborn. Pick up a hand impact driver. That's not a power tool, just a thing you hold and twist with one hand while you bop the end with a hammer. A few bops will get the screws right loose. Otherwise, people have ended up stripping them and making problems for themselves.

When you reassemble, of course you'll spin the rotor all the way down, then start putting the stator back on. At some point, you gotta let go of the rotor, and there's a spring, so it won't be all the way down when you're done, and the valve will be a little open.

You can plug it in and let it close itself when you turn the car on, or you can push it closed with your thumb. The nice thing about pushing with your thumb is you can tell if the rotor whirrs nice and smoothly inside, or if it feels like you got something cockeyed. It's all pretty straightforward.

 

I found a trick for screwing the interior piece down, and keeping it from springing back up when you put the cap over:

Need a crash course in EGR valve disassembly | PriusChat

Post #14 specifically

Also, I sub'd M4x16 socket head cap screws on the install, to facilitate future removal.

 

There's no particular need to keep it from springing back up when you put the cap over.

Having it spring back up gives you the opportunity to push the valve closed with your thumb after reassembly, which lets you confirm you can hear the rotor whirring smoothly inside and nothing is cockeyed, and that's advantageous.