Odd blowdown noise when shutting engine off

Just picked it up Thursday evening with 3 miles on it. Today is Sunday and now has 170 miles. I do not recall hearing this sound until today. Any ideas?

I did search but nothing matched this.

 

Air pump blowing the cat.

 

Searched it up and read a little about this and it blows for about a second to kick moisture out, apparently. Guess I did not notice this the last couple days over my giddy-ness of owning a new 4Runner!

Thanks for the quick reply!

 

It also does it on start up if you listen very carefully.

 

It's been awhile since I read about this system. Does the pump only kick on st engine shutdown.

Is it specifically for the cats?

If it's not emissions related, could we delete it?

Thanks

 

This thread seems to have a ton of info in it.

 

Thank you for the link. Much appreciated.

 

Learn something new 'every' day. Thanks guys

 

It's a new thing, and not only on the 4Runners. Our 2020 Tacoma does it too.

Cheers,

Sean

 

Our 12' Sequoia has it too.

Be nice if it could be eliminated. It would make spark plug changes much easier.

 

Mine farts,too.

 

It’s the turbine flux capacitor rerouting power through the anti-matter plasma conduits. You don’t want to know what happens if you delete this part.

 

Be mindful of what this link and the post it links talk about concerning failure of this system and our runners going into limp mode... the system started appearing on the '05 V8s when they introduced the VVTI system. aka exactly my rig. I literally just installed the Hewitt tech bypass system yesterday to to preempt the issue. The initial sound of it starting to sound like a vacuum over your engine, namely when its cold out and has been off for 7+ hours, is how you identify its starting to go on our older rigs.

Food for thought

 

I got rid of the foam filter and replaced it with a breather filter to keep it from breaking apart and being sucked in.

 

My 2006 Tacoma with the 4-cylinder (2TRFE) engine has the blower motor. Never had any problems with it in 12 yrs of ownership. On that truck it only activates on cold startup, and is supposed to inject air into the exhaust stream in order to heat the catalytic converters up faster. On the 4Runner it does the same, though I'm not sure why it briefly comes on when shutting the engine off.