Sorry dude, long day
Besides . . . I luv ya man
From what I remember it's typically the EGR or VSV, since you replaced the EGR. One is a bitch to replace and the other isn't too bad. Can't remember which is which.
Oh joy, P0401 is back... (and how 80's fail emissions)
- Thread starter nakman
- Start date
Sorry dude, long day
Besides . . . I luv ya man
From what I remember it's typically the EGR or VSV, since you replaced the EGR. One is a bitch to replace and the other isn't too bad. Can't remember which is which.
bigbluefj
Honorary Canuck Member
yup
DaveInDenver
Rising Sun Ham Guru
Are these scan tools an OBD-II thing?
I just get codes like 2 blinks-1.5 second gap-6 blinks for A/F mix malfunction, one blink-1.5 second gap-4 blinks for O2 failure, 4 blinks-1.5 second gap-1 blink for TPS error.
I just get codes like 2 blinks-1.5 second gap-6 blinks for A/F mix malfunction, one blink-1.5 second gap-4 blinks for O2 failure, 4 blinks-1.5 second gap-1 blink for TPS error.
Yessir! Think of them as a way to speak to the soul of your vehicle.
fixed it. sorta
So based loosely on the discussion of disabling the EGR system altogether found in this thread http://forum.ih8mud.com/80-series-tech/308200-disable-egr-system-mostly-toyota-way.html among others, I decided to experiment and have bypassed my faulty temp sensor. It's still installed, but I unplugged in then jumpered the wires in the harness, as if the sensor is "on" all the time now.
So far it's been 2 weeks and about 200 miles, and no CEL
. Also a lot of idling, including the SNR, highway driving, commuting, all the conditions that would have tripped it before. So no CEL means problem solved right? 
So based loosely on the discussion of disabling the EGR system altogether found in this thread http://forum.ih8mud.com/80-series-tech/308200-disable-egr-system-mostly-toyota-way.html among others, I decided to experiment and have bypassed my faulty temp sensor. It's still installed, but I unplugged in then jumpered the wires in the harness, as if the sensor is "on" all the time now.
So far it's been 2 weeks and about 200 miles, and no CEL
. Also a lot of idling, including the SNR, highway driving, commuting, all the conditions that would have tripped it before. So no CEL means problem solved right? Attachments
Red_Chili
Hard Core 4+
Find a way to hide it or make it look normal. The emissions monkeys would be drawn to that like a bear to bait.
I'm sure NakGadget will come up with something.
I'm sure NakGadget will come up with something.
Find a way to hide it or make it look normal. The emissions monkeys would be drawn to that like a bear to bait.
I'm sure NakGadget will come up with something.
Ya think? yeah I'm going to jumper the sensor wires together under the sheathing then plug it back in, you won't be able to tell the wires don't go all the way to the sensor. This was just phase 1 to make sure this was the path I wanted to take..
Hum.. that maybe just my ticket too. Mine comes on randomly then goes a way for a while then rears it's ugly head again.
powderpig
Hard Core 4+
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- Aug 25, 2005
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Well, I had checked the other componets and then checked the temp sensor. I found the sensor to be not reading the exhaust temps(no resistance values with heat). So low flow exhaust gas code when the computer checks it.
First one I have found to have failed.
First one I have found to have failed.
Failed emissions!
Failed emissions, and no, it wasn't the gas cap.
CO measured 14.3325, limit 15.0000 (barely passed)
NOx measured 3.5782, limit 3.5000 (failed)
The documentation suggests that high NOx could be a faulty EGR system. I have been running with the EGR disabled since this thread started, and haven't seen the CEL come on since..
My 80 has also been virtually dormant for a month or so- our daughter moved up in car seats, so the Taco has become the kid hauler.. which left only 2 days/week that I could take the 80 to work, which usually turned into one day. Then a little over two weeks ago I got a ticket in the 80 for expired registration, they must have sent the renewal to my old address and I never even thought to check the license plate
so rather than risk another ticket, I have been just taking the truck until I had time to mess with the 80.
Yesterday I finally made time to swap small tires onto the 80 so I could go to the emissions place, had been a solid two weeks since the 80 was even started. I drove it around for 10 minutes last night, then to work this morning, then over to the emissions place. I am wondering if I just drove it a little more would that warm things up enough to pass.. or do I need to do something more serious here, like actually fix the system I've attempted to bypass. I need to read up more on the mud thread from home tonight.
Here are the test results: 4mb .pdf file
Failed emissions, and no, it wasn't the gas cap.
CO measured 14.3325, limit 15.0000 (barely passed)
NOx measured 3.5782, limit 3.5000 (failed)
The documentation suggests that high NOx could be a faulty EGR system. I have been running with the EGR disabled since this thread started, and haven't seen the CEL come on since..
My 80 has also been virtually dormant for a month or so- our daughter moved up in car seats, so the Taco has become the kid hauler.. which left only 2 days/week that I could take the 80 to work, which usually turned into one day. Then a little over two weeks ago I got a ticket in the 80 for expired registration, they must have sent the renewal to my old address and I never even thought to check the license plate
so rather than risk another ticket, I have been just taking the truck until I had time to mess with the 80.Yesterday I finally made time to swap small tires onto the 80 so I could go to the emissions place, had been a solid two weeks since the 80 was even started. I drove it around for 10 minutes last night, then to work this morning, then over to the emissions place. I am wondering if I just drove it a little more would that warm things up enough to pass.. or do I need to do something more serious here, like actually fix the system I've attempted to bypass. I need to read up more on the mud thread from home tonight.
Here are the test results: 4mb .pdf file
Tch2fly
Rising Sun Member
- Joined
- Apr 1, 2006
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High NOx is the result of high combustion temps, the EGR system inject an inert gas (exhaust) which cools the combustion so a inoperative system could cause the failure (especially since you only missed by a bit).
A cool engine should help not hurt (but could have hurt the CO).
High combustion temps can also be due to a very lean mixture but obviously that is not the case here.
A cool engine should help not hurt (but could have hurt the CO).
High combustion temps can also be due to a very lean mixture but obviously that is not the case here.
I also had high CO- measured 14.3325 out of 15.0000. A little more reading suggests a dirty air cleaner, I think I've got a new one in the tool box so I'll change that out just to be on the safe side. I'm half thinking if I just drive off this tank of gas (probably 5 weeks old?) and fill up with a new tank of 91 octane that I can pass next time no problem..
I'm going to post up to that EGR thread in the mean time just for fun.
I'm going to post up to that EGR thread in the mean time just for fun.
Tch2fly
Rising Sun Member
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I also had high CO- measured 14.3325 out of 15.0000. A little more reading suggests a dirty air cleaner, I think I've got a new one in the tool box so I'll change that out just to be on the safe side.
I saw that (my disclaimer about a lean mixture NOT being a problem here
). Keep in mind that changing any one of the three, NOx/CO/HC usually has some effect on the others.Your rich mixture could also mask a higher combustion temp issue (extra fuel cools the burn) so dropping the CO could actually raise the NOx further.
Mine failed because it was super lean due to bad O2 sensors. New O2 sensor and the richer mixture dropped temps and NOx values.
powderpig
Hard Core 4+
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I think returning the timing to stock or maybe retarding it a little would help as well. Most of us set the base timing to a bit more than stock and this could create some of this as well. I think you also need to drive it a bit more. The fuel has settled some after 3 weeks. The ethenol settles out in due time, so it will also attract some moisture in the tank if it can.
I need to strap on the emission tires and head to the station as well, I am due to work on the 80 as well.
I need to strap on the emission tires and head to the station as well, I am due to work on the 80 as well.
Good luck sir! My e-tires are at the house besides the garage if needed...
Are you saying my timing as been advanced? I mean it's cool with me if so, but there have only been two of us poking around under the hood and I'm pretty sure I don't know how to do that...
That's what I was hoping to hear... I will drive the 80 all week and try to get through most of this old gas, hopefully I don't get pulled over again in the process.
Kevin what kind of tires are they- are they AT's? could I borrow them? My 255 Maxxis sounded like hell on those rollers, everyone in the place looked over to see what was making all the noise and shaking the earth when the guy had it up to speed... it got squirrely a couple times too I was worried he was going to lose it. Maybe a little less rolling resistance would be a good thing for the numbers too?
Bikeman
Hard Core 4+
I would talk to or PM thefatkid, Brian, for some ideas. He has so much experience with EGR related to 80's and the 3.4 conversions he has done, as well as worked for Slee for a time. He basically took the 3 codes my LX had including the 401 code and the next day it passed with flying colors. Not to discredit Robbie, the one and only Cruiser God!
treerootCO
Rising Sun Member
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- Aug 22, 2005
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- 5,422
I have new plugs, wires, cap, rotor, PCV, and air filter if you want to borrow them. They are all Toyota and sitting in a box. Let me know.
When I go to the emissions place, I over inflate the tires for less rolling resistance, change the oil, install new air filter, time the engine to spec, make sure all electrical devices are off for them to test, open all windows and sunroof(they don't throttle it as much if they can hear the engine/tires), drive a minimum of 50 miles on a new tank of gas, and add two bottles of Heet (Red bottle) to the tank. I also have a new gas cap sitting on the shelf because that really burns me when I pass and they fail me on the cap.
When I go to the emissions place, I over inflate the tires for less rolling resistance, change the oil, install new air filter, time the engine to spec, make sure all electrical devices are off for them to test, open all windows and sunroof(they don't throttle it as much if they can hear the engine/tires), drive a minimum of 50 miles on a new tank of gas, and add two bottles of Heet (Red bottle) to the tank. I also have a new gas cap sitting on the shelf because that really burns me when I pass and they fail me on the cap.