Swapping in a Gen 4 Prius' 2ZR Engine into the Prius v

The gas shouldn’t be the big issue stopping the car from running. Five months isn’t that bad on the gas. I think the issue is in the cam sensor or engine control ECU.


You should have a three wire connector. Find the 5v ref wire and the ground. The remaining wire is the signal back to the ECU. Back probe the return path with a volt meter and have an assistant try and power on the car while watching the meter. If the back to ECU reading is greater then 3.5v, I’d get a replacement sensor.


But your other issue, 20% or so battery is a huge issue. There are only so many startup cycles that battery can safely do before it needs a charge. The dealer has to request a grid charger to charge it. The better option is to see if someone on the forum has the prolong charger that you can rent. Yes, you would need your own harness, but it gets the job done. Or check the local salvage yards to see if one has a battery out of a wrecked Prius. Or find someone that is willing to temporarily swap your battery for theirs to charge it back up.

 

Gentleman, I am finally returning after a few months since my Prius swap, I am glad to see some people finding some issues with some of the information provided earlier this year.

I too am getting egr insufficient flow so I have to swap my pins again hopefully that will fix my CEL.

I am also having a much more scary problem which is maybe related.

The engine idles very high on initial start up and then settles down after some driving. Seemingly randomly when you come to a stop at a light the car will start to kill the engine but it won't succeed, it starts huffing and puffing like a lawn mower running out of gas like it can't decide to fully shut off the motor.

This phenomenon manifest itself at any speed when you give the car just the slightest bit of throttle, it swaps rapidly between ice power and electric power.

I just turn the car off when the engine is stuttering and move on with my life praying it will go away on its own(obviously knowing I would be tinkering in warmer weather). The car functions mostly normal and rips hard like the engine is working well.

I will reswap egr wire and see if it solves both of my problems.

I honestly hated how my airbox and intake horn sat on the newer motor so I pulled the intake horn and left only filter box. What does the intake horn even do? I don't care about pure mpg or Toyota engineers or anything just want to know the facts please. Obviously anyone in this thread running a far from stock vehicle right now.

****Edit: I swapped the wires purple and red wires back to stock and went for a test drive and everything seemed normal, the car at least shuts off at a stop and doesn't sound like a dying lawn mower trying to cut power to the engine.

Then later today got on the highway it's behaving strangely on acceleration, lugging at speeds over 40... That was not an issue before. I would say it's worse than the lawnmower shutdown. Maybe will change wheels and tires to be absolutely certain.

 

Seeing these posts about the issues of trying to use the Gen 4 head, EGR, intake, etc makes me glad that I used my Gen 3 head and assorted pieces. Although things have progressed a lot in the nearly two years that have passed since I did mine, it was the better way to go for me.

 

Let’s get this solved! What is your complete setup configuration?




iPhone ?

 

Gen 4 intake
Extended map sensor wire to stock gen 4 spot
Gen 4 throttle body (same part# as gen3)
Gen 4 EGR
No air horn

With stock EGR wiring car behaves strangely when letting off the throttle and sometimes stutters during slight acceleration at speeds 35 mph and above. Letting off after heavy throttle causes it to lug back like an undemanded down shift. No CEL yet but only been about 30mi

When EGR purple and red are swapped the car has a difficult time shutting engine down to run in electric mode. It will kill the engine, rpm drop to near 0 then it quickly goes back to idle and repeats rapidly, just like a lawnmower that is trying to shut down but can't because it keeps getting a few shots of fuel and air. Engine power stutters gently on extremely slight throttle input. Ultimately causes CEL for insufficient flow, my theory is this code is thrown when the car is huffing and puffing trying to shut itself down properly. I have gone maybe 200 or so miles without CEL but never many miles without showing symptoms. Sometimes car shuts down properly, sometimes slight throttle input is received without any stutters.

With all this stuff going on I'm wondering maybe I just need to put intake horn back on to smooth out intake airflow, I see people with cold intakes and not having any issues so I didn't think the delete would have dramatic effects like this.

Either EGR configuration yields mostly normal performance from engine at all except closing and slightly open throttle ranges.

The air horn just won't sit crisply on the gen 4 intake and motor and I have just been to lazy to trim and make fit.

 

No matter what you do, if you don't fix the p0343 code, the engine failed to start would still e there, and vehicle would keep going off.
The p0343 isn't about timing misalignment. Check the harness on the sensor itself (may have chamfered or chewed by rats). Also check to see if you've got an open or short circuits on that circuit leading to the ECU. Finally, replaced the camshaft/crankshaft sensors.

 

What is the part number of the EGR valve?

There was a TSB for early Gen 3 Prius and Prius v (T-SB-0027-16) that involved installing a newer EGR valve (04004-58137) and reflashing the ECM with new firmware for driving the newer valve. For a Prius V, the updated firmware would have calibration number 34725500 or above.

 

He is running a 4th Gen EGR. Very good info concerning the EGR campaign - need to check my drawer full of old EGR’s for a visual confirmation


iPhone ?

 

How can I flash it? I have a pretty good code reader. I would want to be able to flash back to stock if need be as well. looks like that is not the EGR part number for gen4 either.

What if I just flashed 2016 entirely?

 

Maybe dealership only could do it. But with everything EGR being 4th gen, and 3rd gen CPU's, would they even touch it??

 

Other people running gen 4 no flash so I'm not giving up that easy car did not have this issue before swap.

 

Maybe it’s just a bad EGR valve and needs to be changed?

 

Here's an old post that touched on that.

Hmm, that complicates matters. Which EGR valve was on your older engine, the pre-TSB or post-TSB one?

That would be adventurous. I might not start without first taking apart my ECM and a 2016 ECM to make sure they use the same processor chip, same amount of memory, etc. Otherwise trying to put the 2016 firmware on it might not go so well, even if Techstream allows it in the first place.

 

Old EGR valve is in a scrapyard somewhere with the old engine.

This gen 4 EGR valve has 40k miles on it, is there really concern that it's bad? Perhaps but I don't want to throw away $200 just yet

 

Took out the filter. Same kind of symptoms as before but actually a little better. Car is stuttering when accellerating

 

I wish I kept old EGR lol maybe the firmware update would help. Maybe I just need to restrict airflow more with the air horn

Anybody know what the air horn does besides scoop colder air from behind the headlight? Like what does the chamber do, specifically allow air to only flow a certain rate probably, maybe screwing with that is messing with tune worse than predicted?

But if anyone has ever run a Prius no air horn before without these results it must be something with EGR

Does anyone tune prius ecus for EGR delete or anything like that?

 

I assume there's nothing wrong with it, just a changed design requiring a changed algorithm in the firmware to control it.

 

The air horn has a couple mufflers to dampen noise. I run without it and find the engine is still extremely quiet. You can check my gallery for pictures.

Pixel XL ?

 

Is there any info available to support that? I'm not trying to be contentious, it just seems a can of worms, to have to match hardware and software. Could it be there is no software change for the revised EGR valve? Say it just flows better, is less clog prone? Due to some shape tweak?

 

What if I just completely unplug EGR for now?