Engine Sputter at start for 15-20 seconds

Welcome to the knock club, we're always accepting new members.

Check the egr pipe, if it's coated with a thick carbon layer, the entire egr circuit needs to be cleaned. After that, install an OCC & dump it every oil change. Had it done to mine, highly recommended.

 

What's the miles on it? EGR cleaning is something I did at 70K kms. Admittedly a little early, but I'd recommend to do by 100K kms for sure. An Oil Catch Can is good from the get go, traps all the gunk your PCV is otherwise dumping into the intake. Boiler plate text follows:

The simplest way to see where you're at, is to check the degree of carbon build up in the EGR pipe, a stainless steel connecting pipe between the EGR valve and intake manifold. Watch @NutzAboutBolts video #16 here:

Nutz About Bolts Prius Maintenance Videos | PriusChat

Two or three other videos linked there too, for the full cleaning of the intake manifold, full EGR clean, and Oil Catch Can install.

Good thread:

EGR & Intake Manifold Clean Results | PriusChat

Another:

Oil Catch Can, Eliminate that knock! | PriusChat

Some tools worth having:

E8 Torx socket (mandatory)
E6 Torx socket (optional, but good to have, to remove the throttle body studs from intake manifold)
3/8" ratchet wrench, regular and long handle, flex head, you can never have enough (or 1/2 plus reducer)
1/4" ratchet wrench, or 3/8" to 1/4" reducer
Ratchet extensions: you can never have enough
Long needle nose piers, straight and bent tip
Ratcheting 12mm box wrench (optional, but makes disconnection of the EGR cooler from exhaust easier)
Torque wrench (3/8" and 1/4" both good to have)
Floor jack and safety stands (or ramps): basically some method to raise front, if you need to take underpanel off, which you may need to, both for access and to recover dropped items.

 

I didnt know, you didnt know.

And I just realized you had this thread going.

It MIGHT just be possible that the above junky start was due to shutting off while the engine was running???
This can cause it to do that funkiness.

But with the above posters, it is a common occurrence that should be addressed with those checks/cleanings/occ
As I mentioned in the other thread about this problem Toyota fudged up.

But if it was first time, and the possible shut off of the car was with engine running, and as the weather is cold out now,
it may be possible to hold off on it, but needs attended soon enough.

 

Maybe just do the pipe check first, so you have some idea.

 

Well they did somewhat of a change to finish out Gen3, not sure to combat the issue or try to alleviate some of it.
in 14 the pistons were updated, and in 15 the rings were then updated too.

As for 16 when Gen4 came about, they did do some changes
I believe @Raytheeagle could break Gen4 down also in comparison with Gen3

 

If we are talking about egr circuit land, they moved the branch that sends back to the egr cooler to after the catalytic converter.

Cleansed gases should help with less plugging and other related issues.

But the access to the egr cooler is much worse:


So the answer to the attention to detail question is a tough one.

 

Well hopefully you have years to go until detail is needed

 

Hopefully.

But I’ll probably take a peek around 100k miles.

I like to stay ahead of the wave not ride it.

 

Toyota also roughly doubled the cross-sectional area of the EGR components.

 

A lot of victims usually post here with knocks that leads to loss of coolant then transitions to blown head gasket that cost a few grand for a motor replacement so start saving up. Reasons why I don’t recommend turd gens anymore.

 

Here's Ray's 4th gen pics again, the first one rotated to normal orientation. For clues as to where the close-up is, look at the orange plastic brackets:

An Oil Catch Can is not going to prevent Exhaust Gas Recirculation clogging. It "may" slow it, and at least equally probable: it may slow the build up of gunk on the piston rings.

To keep the EGR in good working order on a 3rd gen, periodic cleaning (both the EGR and Intake Manifold) is the ticket.

 

Yeah clean first, in particular the Intake Manifold, then OCC install. The intake manifold will be awash in the PCV gunk, so good to clean it and then install the OCC to prevent reoccurence.

@Raytheeagle was saying 50K miles. Which sounds sensible. I'd be sitting on my hands pretty much forever waiting for that, so probably 50K kms for me, lol.

Again, I did ours first time at 70K kms, and it was "modestly" clogged. I get the sense it's kinda like the coolant change interval, after the first (long) interval, you want to do subsequent services more frequently?

Again: checking the EGR pipe is easy to do, to get your feet wet, see where it's at.