I replaced the egr valve on the prius and after driving 100 miles the when i do emissions test it continues to fail over and over because egr system is not ready, and tips to get egr ready? Last year before it went bad it would ready around 70 miles should i drive it more? Also i did not change the egr cooler just the egr valve. I am not a pro mechanic i just do DIY repairs when they seems simple enough. My car has been sitting around for a month now and i use it for work any help would be great!
The right confirmation driving pattern is shown in the repair manual section for the P0401 trouble code. See if you can find a copy of that, and then drive the indicated pattern. Toyota Service Information and Where To Find It | PriusChat The status (if you're using a smart enough scan tool to show you the actual status) can just be NOT READY (the car just hasn't had the confirmation pattern driven and a chance to run the test yet), OK (the test completed and passed), NG (the test completed and there's still a flow problem), or UNKNOWN (because some other problem, weird MAP sensor reading for example, is preventing the test being run). So clearly what you need to do depends on the actual status. If it gets to OK you're good to go. If it gets to NG you know there's still an EGR problem and you deal with that. If it goes to UNKNOWN then you have to figure out why the test can't run, and deal with that. If it's only NOT READY, just make sure you drive the whole confirmation pattern.
This is your problem—non-OEM EGR valves simply do not function as intended. There are 3 Amazon reviews of the unit you purchased, and they are either 1 or 2 stars, and they all report the valve malfunctioning about a week after installation. At least a couple of other members here have run into the very same issue over the past month. Just bite the bullet and spring for OEM, or pull one from a junkyard.
Hopefully you still have the original egr valve. I cleaned mine and reused it. Some fail and aren't reusable, but not always.
With the stock EGR valve, take the black cap off* and check the condition of the interior, in particular the "ski ramp" thing. I think @ChapmanF has a photo handy, showing what can happen to that. * The hold-down screws on the cap will likely be trouble, prone to strip the holes. A impact screwdriver, the kind you wack with a hammer, is good. Set the valve on solid wood blocking, so that the studs on the bottom are not touching anything, and give the screws good taps. Just for insurance I replaced the screws on ours, with M6x16 mm machine screws. They had socket-head caps, requiring an Allen key style driver, much less prone to strip.
Should you need to re-purchase a new EGR valve, absolutely do yourself a favor and get the Toyota OEM one. But in addition, get the EGR valve kit (part no. 04004-58137) as it's cheaper than buying the valve alone. Also, be aware that the latest EGR valves require a software update via Techstream, which would likely need a dealer visit. This is assuming your old OEM valve was original from 2010. If it was ever replaced under warranty or for a TSB, the software MAY be up-to-date.
The updated firmware version is announced in the same TSB that announces the updated EGR valve. The same updated firmware version is announced in a different TSB that announces a new intake manifold. The valve TSB doesn't mention the manifold, and the manifold TSB doesn't mention the valve. I infer that the firmware update has some improvements that are good to have and probably improves some of the same issues the manifold and valve do. But given that the updated firmware has to be able to work with the new manifold and the old valve, or the old manifold and the new valve, and it has no way of knowing which of either you have, I would not worry about stuff failing to work or anything, just because the firmware didn't get updated.
i am waiting on oem egr and cooler to come in and will replace and see if it will get ready then. Also for the egr cooler there is a bolt i cant seem to get to that is at the back bottom any tips on this?
To get fingers on it, it's easier to reach around from the back with your left hand. It is "just" possible to get a socket and extension on that nut. There's a lot of stuff in the way, and it takes just the right combo on a ratchet wrench; IIRC it was something like a deep socket and a 1.5" extension, plus the ratchet wrench I was using had a swivel head. Once you get it off, leave it off; there's plenty more fasteners holding the assembly fast. Removing the stud that nut screws on has benefits too: If you're leave that nut off, the stud is no longer doing much, and with it removed, plus the frontmost stud/nut combo and top bolt removed, and the two rearmost nuts removed (at cooler to exhaust manifold connection), you can then extricate the cooler without needing to remove the rear two studs. Removing those rearmost studs is a pain, and leaving them on prevents the rearmost gasket from possibly dropping down, getting lost. There is a slight clearance issue as you pull the cooler forward: it'll bump a rigid tube (part of the gas vapour return to intake manifold, if I'm not mistaken), but loosening and shifting it's mounting bracket provides enough clearance for the cooler to squeak by. See second EGR link in my signature, for tips on preventing coolant spillage. On a phone, turn it landscape to see signature.
As soon as parts arrive i will keep this post updated. I hope that will at least get the emissions passing after. Ive been able to weasel around the other codes but the egr readiness is the only thing causing it to fail.
If you have one of the officially supported cables, you could get a two-day subscription to Techstream which would let you flash the new firmware. Or you might be able to get the dealer to do it. However, as Chapman noted, it is not an absolute necessity, and you'll be fine with whatever firmware you're already on.
Also, even if I theoretically could do it myself, I personally handle ECU reflashes in the "hello dealer? can I come in and have you update my ECM to calibration 34715700?" fashion. They charge about an hour of shop time, and if they brick it, it's their problem—priceless. It might be worth updating to that calibration even without a new EGR or manifold, just for other fixes it might contain. There was an issue fixed earlier in 34715400 that could cause backfires damaging the evap purge valve and blowing hoses off the manifold—Georgina has mentioned that one before. Those calibration numbers are for a 2010. For other years, see the TSBs to see what the appropriate calibrations are.
