rough start, throws P0138, P2195 codes

It's too cold to be working on the car. I would see if the codes return before I start to worry. 02 sensors won't disable your car. How many miles are on your car?

 

have you already replaced the manifold?

 

In my opinion, this is caused by condensation in the exhaust wetting or freezing on to one or more of the exhaust gas sensors.
Although the sensors are electrically heated, that is sometimes not sufficient to dry or thaw the sensors during startup.

 

Are you out due to time on the 5 year, 100,000 km powertrain warranty?

(I guess if Toyota's stumped, it's a moot point.)

 

i don't know how well the fix worked, there's a huge thread. but some still have it happen and even 2012 - 2015 models.

 

IMHO, you had the right idea to reset the codes and see if the problem recurs. However, being that close to warranty expiration, the dealer might have been able to test the sensors before replacing them (I assume they can be tested to some degree). The advantage to having taken it in would be that you'd have a record of the problem and that might have helped if the problem recurred shortly after the warranty was up, assuming it would have been covered by the warranty in the first place.

 

My EGR valve recently was replaced and while it was acting up there were a couple times that the turning over of the motor was VERY rough. And while running the motor would shake.

 

Started my car this morning at -15F and It had a very very rough banging/knocking sound. Got in shut it off and started it again and it came out of it. Makes me nervous, but the check engine light never came on. I've started it before on colder days with -20F and it starts fine with no problems. Sure hope this doesn't lead to anything serious happening. Someone suggested putting some HEAT in the gas. Kinda makes me nervous as I'm not sure about adding anything to the tank. Will wait and see what happens tomorrow morning.

 

how bout a block heater?

 

I can verify that as of 12/29/14, the day I had my 2011 at the dealer for this type of startup rattle/miss fire, they are no longer replacing the manifold. The TSB is showing in their system as withdrawn, if I remember correctly.

What's more, they maintain that an engine misfire is not part of the 60k/5 year powertrain warranty. Misfire would be under ignition and that's not part of the power train.

Made me real happy. Toyota does not seem to officially admit that the cold start misfire exists. They checked the plugs and coils and cancelled out the codes and sent me on my way, minus $99

But the start up rattle has happened to me only once, and it happened in the classic setting: I had driven the car only a few feet three days earlier and shut the engine off after perhaps 30 seconds, while it was still in its "warmup) phase. Then it sat in a very cold building at about 15 degree for 4 days. Upon startup, clearly was miss firing. Lasted for maybe 15 seconds.

I think the condensation theory is the correct one. "Heat" is made to pull water out of gas lines and tank. Its basically alcohol. So these days, with so much ethanol in our fuel supplies, these is no role for Heat. As much as the condensation is indeed water, its water from combustion that is slipping back into the intake manifold due to the strangeness of the Atikinson cycle engines we have.

If it happens often to you, you need to start making sure that you don't shut the engine off unless its fully warmed up. This is reputed to stop the occurrences of the cold start misfire.

 

$99 to check the plugs and coils is a deal. It's a lot of work. .....if they really did it

 

I don't know what they really did to check them. But they did take things apart and moved the #1 coil to 2 and #1 spark plug to 3. But it would not throw any other codes from that point on -- probably since the coils and plugs are not the cause of the cylinder 1 misfire after cold soak. In fact, Toyota does not seem to acknowledge right now that the phenomenon exists. Except it does.....

This has actually shaken my faith in Toyota just a tad. I've had really good luck with my Toyota products through the years. Bought the 2011 Prius expecting the same. And to be fair, its not dumped me or really cost anything except gas, oil and tires. Except for the $99 But its making more noise (different noise than the startup misfire)....

Anyhow, I *think* the startup misfire can be avoided by recognizing the atmospheric and usage phenomenon. Just do not park a cold vehicle after a few seconds of engine run time, in the cold. That's actually been solid advice for decades, but we all know that you can get away with it usually in modern vehicles.

 

That's all the more reason why it would be helpful if (as others have suggested in other threads) they'd allow moving the car a very short distance at very low speeds without starting the engine, as long as battery state of charge, etc. allows, even at low ambient temperatures.

 

You can in fact move the car as far (and as fast) as you like without starting the engine... as long as you turn it off again within about 12 seconds.

I can admit to (and I imagine others will too) moving the car for 10 seconds, turning it off and back on, and then moving it for another 10 seconds, in order to move it somewhere in EV when below the 68°F threshold for EV mode.

In fact, given that the 0-60 time is quoted as under 12 seconds......