I need help. My registration expires on Thursday and I need to pass emissions first. I have EVAP leak codes P0442, P0446, and cat inefficiency code P0420. I replaced the gas cap twice and that didn't clear the leak codes. I then took it to the dealer for diagnosis and they told me it was the ORVR check valve. I replaced the valve and gasket, reset the codes and performed a drive cycle and both leak codes came back along with the P0420. I did notice when I replaced that valve that the larger hose connected to the valve has an o-ring in it and the fit didn't seem very tight. Could that o-ring be leaking? Should I take it back to the dealer, take it somewhere else, or is there another common failure point for these codes that I should check?
jdborchert
There are quite a few threads dedicated to these codes. Seek(search) and ye shall find. But here is a short summary...
P0442 and P0446 are Evap system codes. Many people get these from leaks in the Evap system. On my Sienna it was a leaky canister. Have your system smoke tested for leaks. Did you use an OEM Toyota gas cap? An aftermarket cap may not properly seal. If you have a high mileage Sienna or drive in salty ice roads, it is likely that your canister has a leak by now.
P0420 is set when the catalyst system is deemed (by the ECU) to be below threshold. ECUs on 2001-03 were defective and set the code when the catalyst was often still good. P0420 can be caused by a number of other issues. To eliminate the code, some have replaced the pre-cat O2(actually AF) sensors. Others have replaced the rear O2 sensor. Exhaust leaks around the pre-cats/cats can also cause this problem. The main rear cat or one of the pre-cats could be below threshold too. Toyota will want to sell you either an updated ECU for $1500, a pre-cat y-pipe, and/or a main cat for about $1500. If you try a shotgun approach and replace O2 sensors, only use OEM Denso. If you buy cats, only buy OEM Toyota cats unless you have upgraded your ECU(on 2001-03). If you get the corrected ECU, you can then use cheaper aftermarket cats.
P0442 and P0446 are Evap system codes. Many people get these from leaks in the Evap system. On my Sienna it was a leaky canister. Have your system smoke tested for leaks. Did you use an OEM Toyota gas cap? An aftermarket cap may not properly seal. If you have a high mileage Sienna or drive in salty ice roads, it is likely that your canister has a leak by now.
P0420 is set when the catalyst system is deemed (by the ECU) to be below threshold. ECUs on 2001-03 were defective and set the code when the catalyst was often still good. P0420 can be caused by a number of other issues. To eliminate the code, some have replaced the pre-cat O2(actually AF) sensors. Others have replaced the rear O2 sensor. Exhaust leaks around the pre-cats/cats can also cause this problem. The main rear cat or one of the pre-cats could be below threshold too. Toyota will want to sell you either an updated ECU for $1500, a pre-cat y-pipe, and/or a main cat for about $1500. If you try a shotgun approach and replace O2 sensors, only use OEM Denso. If you buy cats, only buy OEM Toyota cats unless you have upgraded your ECU(on 2001-03). If you get the corrected ECU, you can then use cheaper aftermarket cats.
+1 RobertB is correct.
What year is your van?
On my 2002, my exhaust emissions code P0420 was solved by replacing the oxygen sensor. My P1135 and P1155 were solved by replacing my A/F ratio sensors.
My P0440, P0442, and P0446 were solved by replacing my charcoal canister.
Check also into waivers for your state emissions program, since you don't have the luxury of time. Here in Connecticut, for instance, if over $865 is spent on emissions repairs, trying to fix an emissions problem, you may get a cost waiver. The catch is that this work must be done by a state-certified emissions repair technician.
What year is your van?
On my 2002, my exhaust emissions code P0420 was solved by replacing the oxygen sensor. My P1135 and P1155 were solved by replacing my A/F ratio sensors.
My P0440, P0442, and P0446 were solved by replacing my charcoal canister.
Check also into waivers for your state emissions program, since you don't have the luxury of time. Here in Connecticut, for instance, if over $865 is spent on emissions repairs, trying to fix an emissions problem, you may get a cost waiver. The catch is that this work must be done by a state-certified emissions repair technician.
The van is a 2003. I used a Toyota gas cap. Is there any way to get an updated ECU from a salvage yard? I have previously replaced the bank 2 A/F sensor and the rear O2 sensor. Is there any way to verify the operation of the bank 1 A/F sensor before I replace it? I have a scan tool with live data capability.
I posted more info about the ECUs on the Toyota Nation forum earlier today.... but since you asked about ECUs from a salvage yard, I'll address that here. Yes, you can get one from a salvage yard, you would need part number 89661–08081 or 89661–08082. 89661–08082 is the very latest version of it, but 89661–08081 should have the cat update too. The biggest problem in getting a used ECU is finding one first! The next issue, is making it work in your Sienna. If your Sienna does not have an immobilizer, and the salvaged Sienna also does not have an immobilizer, then you just plug it in and go. If the salvaged ECU came out of a Sienna without an immobilizer, yet your Sienna has one, you have to program the keys in when you install it. There is a procedure to do this. I didn't have to do it on mine as I do not have an immobilizer. A locksmith might help with that if needed. It gets really tricky if the salvaged ECU came out of a Sienna with an immobilizer. In that case you have to reprogram the 93C56 chip in the ECU back to a "virgin" state. This is not rocket science, but you have to have a method to reprogram that chip. You usually have to remove it from the motherboard first to program it. This requires a soldering iron with a fine point and a desoldering tool. Then you attach an SOIC8 clip to it and download the new data to it. It is a tiny surface mount chip with 8 pins. It only holds 256 bytes of transponder codes from the keys of the salvaged Sienna. I have published the values for what it took for my 2001 Sienna somewhere on the forum. But if you want to go that route, I can find and post them again.
To tell if you have an immobilizer, look at your keys. If a fully metal key will start the car, it does not have an immobilizer. If the key has a plastic cover with an embedded transponder then you do have the immobilizer. I think there might be a red dot on it where the transponder slides into the plastic. I don't have one to look at however.
The A/F sensors have a code for the heater circuit failure which is separate from the other Cat system codes. However, they can get "lazy" with age. There is a resistance check that can be performed. But it probably would have thrown the code if that had already failed.
To tell if you have an immobilizer, look at your keys. If a fully metal key will start the car, it does not have an immobilizer. If the key has a plastic cover with an embedded transponder then you do have the immobilizer. I think there might be a red dot on it where the transponder slides into the plastic. I don't have one to look at however.
The A/F sensors have a code for the heater circuit failure which is separate from the other Cat system codes. However, they can get "lazy" with age. There is a resistance check that can be performed. But it probably would have thrown the code if that had already failed.
Did you use Denso (or Toyota) branded sensors?
You can't really verify operation of the A/F sensor. If it's OEM, and on the hot Bank 1, it's certainly quite aged by now. The Bank 1 Sensor 1 is notoriously difficult to remove, often seized in place, in an inaccessible location, unlike the trivial-to-replace B2S1. Use lots of the best penetrating lube, something like Kroil, and you may be fortunate enough to unscrew it without ruining the threads on the bung.
If you are lucky enough to find a salvaged updated ECU, you may be stymied by immobilizer issues. There's a thread here, and also near the one you started on Toyota Nation, dealing with the immobilizer system...
For the evaporative emissions codes, it's never as easy as the gas cap!
Also about your state emissions, you may have a grace period from your "due date" to be tested. In Connecticut, I think it's 90 days.
You can't really verify operation of the A/F sensor. If it's OEM, and on the hot Bank 1, it's certainly quite aged by now. The Bank 1 Sensor 1 is notoriously difficult to remove, often seized in place, in an inaccessible location, unlike the trivial-to-replace B2S1. Use lots of the best penetrating lube, something like Kroil, and you may be fortunate enough to unscrew it without ruining the threads on the bung.
If you are lucky enough to find a salvaged updated ECU, you may be stymied by immobilizer issues. There's a thread here, and also near the one you started on Toyota Nation, dealing with the immobilizer system...
For the evaporative emissions codes, it's never as easy as the gas cap!
Also about your state emissions, you may have a grace period from your "due date" to be tested. In Connecticut, I think it's 90 days.
I know I used a Denso A/F sensor, the O2 sensor may have been Bosch. And now that I look back at my records and remember the PITA it was to replace it, it actually was B1S1 on the rear bank by the firewall. That was not fun. I haven't replaced the front Bank 2 sensor. And my van doesn't have an immobilizer.
I also found out that I have a 5-day grace period after my registration expires before I am out of compliance. I also technically have 6 months (or until I get a citation) to get my van registered. So I do have a little time. I dropped it of today at a shop to get the EVAP leak checked out so hopefully I can get that taken care of and then get it inspected before the P0420 triggers the MIL (it has so far stayed in pending and not turned on the MIL).
I also found out that I have a 5-day grace period after my registration expires before I am out of compliance. I also technically have 6 months (or until I get a citation) to get my van registered. So I do have a little time. I dropped it of today at a shop to get the EVAP leak checked out so hopefully I can get that taken care of and then get it inspected before the P0420 triggers the MIL (it has so far stayed in pending and not turned on the MIL).
It can take a while to trigger a P0420 if you are driving short distances. Ours was being driven only about 15 minutes at a time. This wasn't usually enough to trigger the Cat test in the ECU. But if you can get the Evap problem fixed, that would give you time to fix the catalyst issue. I think I paid somewhere around $500 to 600 to have the canister replaced 6 or 7 years ago. I would do it myself now.
Oh, I also have a Bosch O2 sensor, and Denso AF sensors. The Bosch works fine. If I had to do it again, I would have bought a Denso for more perfect OEM compatibility.
Oh, I also have a Bosch O2 sensor, and Denso AF sensors. The Bosch works fine. If I had to do it again, I would have bought a Denso for more perfect OEM compatibility.
Maybe you'll be lucky and get a "ready" on the catalyst test. If possible, a long trip on the highway seems to be best to get a good result, in my personal experience (like 2, 50-mile trips).
Things to check are the tightness of the connection around the oxygen sensor--the two mounting studs often are rusted, except in warm climates. And then you may consider replacing the Bank 2 sensor, or at least test its resistance. You can check its resistance, given its accessible location, quite easily. Just use care disconnecting the wire harness.
Do you have the repair manual? You can find one if you look under "General Discussion."
Things to check are the tightness of the connection around the oxygen sensor--the two mounting studs often are rusted, except in warm climates. And then you may consider replacing the Bank 2 sensor, or at least test its resistance. You can check its resistance, given its accessible location, quite easily. Just use care disconnecting the wire harness.
Do you have the repair manual? You can find one if you look under "General Discussion."
So I took the van to a shop to get a smoke test and they found no leaks. They said it passed all of their service bay pressure tests. I don't know what to do other than try to replace the charcoal canister that many have said was the cause of their P0446 codes.
Regarding the P0420, I did find a TSB that seems to indicate that my '03 Sienna ECU can be reprogrammed.
http://obdrus.ru/d/787731/d/techstream-ecu-flash-reprogramming-procedure.pdf
Has anybody seen this? Is it possible to flash my ECU to fix the P0420 code?
Right now the codes have been cleared and all monitors are ready except EVAP and CAT. I found a TSB for drive patterns to set the readiness monitors but it is for '96-'02.
http://www.obdclearinghouse.com/documents/newdocuments/toyota/TSB_EG003-02_%28revised%29.pdf
Does anybody know if this applies to '03 as well. I'm hoping I can get the CAT monitor to pass since the P0420 is typically intermittent. Then I can pass emissions and have more time to figure everything out.
Regarding the P0420, I did find a TSB that seems to indicate that my '03 Sienna ECU can be reprogrammed.
http://obdrus.ru/d/787731/d/techstream-ecu-flash-reprogramming-procedure.pdf
Has anybody seen this? Is it possible to flash my ECU to fix the P0420 code?
Right now the codes have been cleared and all monitors are ready except EVAP and CAT. I found a TSB for drive patterns to set the readiness monitors but it is for '96-'02.
http://www.obdclearinghouse.com/documents/newdocuments/toyota/TSB_EG003-02_%28revised%29.pdf
Does anybody know if this applies to '03 as well. I'm hoping I can get the CAT monitor to pass since the P0420 is typically intermittent. Then I can pass emissions and have more time to figure everything out.
Unfortunately, our ECUs aren't flashable.
The 2003 is essentially a 2002 model--there were a few changes mid-2002 to a few things, like the PCV system. The 2002 drive patterns will work for you.
I've found that there seems to be a different test for the catalyst monitor, based on vehicle speed, at least according to the test results I can see in Techstream. On my van, my test results are closer to the no-good emissions cutoff when I drive around town; there's more room to spare, so to speak, when a test completes on the highway. (That sort-of contradicts the drive patterns listed by Toyota, but I do get my tests to run on the highway--I'm fortunate enough to have a monthly 95-mile highway trip. I can reset my monitors before the trip, and after I get home, after 190 miles, the catalyst monitor is completed.)
If you replace the canister yourself, and you live in a road-salt area (don't think you mentioned your state), you'll need a lot of penetrating oil, and patience, to remove the nuts on the "protector." On my 2002 van, everything checked out fine, and it was the canister (which had checked out fine).
The 2003 is essentially a 2002 model--there were a few changes mid-2002 to a few things, like the PCV system. The 2002 drive patterns will work for you.
I've found that there seems to be a different test for the catalyst monitor, based on vehicle speed, at least according to the test results I can see in Techstream. On my van, my test results are closer to the no-good emissions cutoff when I drive around town; there's more room to spare, so to speak, when a test completes on the highway. (That sort-of contradicts the drive patterns listed by Toyota, but I do get my tests to run on the highway--I'm fortunate enough to have a monthly 95-mile highway trip. I can reset my monitors before the trip, and after I get home, after 190 miles, the catalyst monitor is completed.)
If you replace the canister yourself, and you live in a road-salt area (don't think you mentioned your state), you'll need a lot of penetrating oil, and patience, to remove the nuts on the "protector." On my 2002 van, everything checked out fine, and it was the canister (which had checked out fine).
UPDATE - My van passed inspection!!! After getting it back from the shop that did the smoke test with no leaks found the codes had been cleared and I was just hoping to get either the CAT or EVAP monitor to pass so I could get it inspected. While waiting for the monitors to set I cleared out an EVAP line per TSB EG007-05. The P0401 code came back in pending codes so I picked up two bottles of Guaranteed to Pass and put those in with a full tank of gas. I ran through that tank halfway through a 120 mile round trip this weekend. After refilling and returning home the CAT monitor finally passed when I was only a couple of miles from home. The van passed inspection yesterday. So far the EVAP codes have not returned after the smoke test. I'm not sure if the ORVR valve that I replaced really was the culprit and it just needed time to seal the gasket or if they haven't returned because the EVAP monitor hasn't run. Either way I now have another year to figure things out if any codes come back.
Great news! Those highway trips do run a test that's easier to pass. Now you don't have an inspection hanging over your head if/when codes come back.
I had the P442 along with P420 P430 intermittently. I tried the gas cap replacement, but the problem was actually in the egr lines under the engine cover. I replaced the three primary ones (the one on the right side of the picture was cracked and the culprit) with 5/16in inner diameter fuel line hose and clamps.... all for less than $10.
Attachments
This is an old thread, but that's such a nice picture, and is exactly what I am doing and the problem I had.
After pulling that tube on the right off, first to replace the rear spark plugs (it ripped this first time) and then for the knock sensors and for the coolant leak in the V of the engine, that hose ripped at the end. FWIW I tried to grab the line off of 3 engines at the junk yard, and all 3 ripped. The line measures at just a hair under 5/16". I think the 5/16" fuel and evaporative hose at Autozone will work, for $3/foot.
The original is listed as 23826 in the picture at 2006 TOYOTA SIENNA WAGON, 5-DOOR, XLE 3300CC 24-VALVE DOHC EFI, AUTOMATIC VACUUM PIPING and https://images.simplepart.com/images/parts/toyota/fullsize/173570C.jpg
After pulling that tube on the right off, first to replace the rear spark plugs (it ripped this first time) and then for the knock sensors and for the coolant leak in the V of the engine, that hose ripped at the end. FWIW I tried to grab the line off of 3 engines at the junk yard, and all 3 ripped. The line measures at just a hair under 5/16". I think the 5/16" fuel and evaporative hose at Autozone will work, for $3/foot.
The original is listed as 23826 in the picture at 2006 TOYOTA SIENNA WAGON, 5-DOOR, XLE 3300CC 24-VALVE DOHC EFI, AUTOMATIC VACUUM PIPING and https://images.simplepart.com/images/parts/toyota/fullsize/173570C.jpg
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