Prius (2004-09) :: Code P0420 - Diagnosing O2 Voltages And Cat Temperature
Jun 24, 2016
I have P0420 on my 06 prius with 220K miles. I reset it and it comes back after roughly 50 miles-ish. I have freeze frame data when the code is thrown. I read live data at 2500 rpm while the car is warm, and have all the data on the video link below.
My upstream O2 voltage is 3.1-3.3V. Downstream is .2-.4V. I understand that the downstream should be steady, and the upstream should fluctuate and read something between .1V-1V.
I have also taken thermal temp gauge and measured across both cats and readings downstream seem to be only slightly higher (+50F). It should be ALOT higher shouldn't it?
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2007 Prius with 112k. It's getting the red triangle and check engine with code P3012. My understanding is P3012 points to 'Battery Block 2 Becomes Weak'. Battery block 2 is the 3rd and 4th modules counting from the end where the ECU is. These two modules test out the same as the other 26 modules in this pack, ranging from 7.40 to 7.46.
I got them this low by running A/C on high with car in neutral, hoping the bad module would show up. (Neutral prevents engine from charging HV battery.)
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I replaced a couple modules in my battery pack several months ago and it was working great until a few weeks ago I drove it after it had been sitting a couple days and it threw code P3006. I logged all the block voltages with Torque while I put the battery under load and found a potential issue but I'm not sure how relevant it is. Block 16 on on line 283 drops from 1624 to 1296(the refresh rate is rather poor so it's about 7 seconds between readings) while the other blocks only drop to about 1450. Is this significant or are anomalies like this normal? If this is an issue, how would I go about fixing it? I don't have the equipment to do a full rebalance, just a single channel charger. I did make sure that the voltages on the modules I replaced were consistent with the pack.
I plotted the data here.
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Just picked up a 2005 with 146k and full Toyota service history, although seems a steering recall was not done. Will run it to the dealer today to check. I need to decide a.s.a.p. if I am keeping the car or not (I know the seller, he will take it back)
Anyway to cut a long story short, two questions.
1) Car had P3190 and P0420 when I got it. Seller reset, drove home and within 5 minutes on the road the CEL was back on. Checked the codes at home and see only a P0420. Much to worry about? Seems this might be big (Cat) or small (O2). Car getting great mileage - 60mpg at 60mph and it seems to be running great. Should I worry or forget about it? Note I am in Florida with no inspections.
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So I bought a used 2005 Prius back in August it had 88,000 miles on it and was out of warranty. But I had a full inspection on it and the car was in great shape. Well, after a few months of driving, I got the P0420 error. I took it into my mechanic who cleared the code and told me to call him if it came back on. It came back on, then I cleared it myself, and it came back on again. So it was confirmed that I had a bad catalytic converter.
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I checked out a 2006 Prius yesterday a guy is selling. It had the CEL on (not sure why somebody would try and sell a car with that, but anyway). He said that it's because they get gas at a station that consistently doesn't tighten the gas cap enough but by the time the tank is down to 1-2 bars the light always goes away. Although I don't doubt his story, I absolutely doubted the cause. So I took it to get the code pulled and it was P0420, which is catalytic converter threshold below efficiency.
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So today my CEL came on. I immediately looked at my mileage and I was EXACTLY at 500m past my oil change the other day. I checked the dip stick and lo and behold, it was about 3/4" past the full marker. I took it back to the oil change place and had them drain it down to a good level.
I had driven from NH to NY this week. I filled up my gas tank on my way home from NY. Gas cap was on nice and tight for sure.
The code is still on (not sure how many miles or drive cycles is required) for something to clear. I figured it was perhaps due to too much oil added. I decided a few hours later to take it to AutoZone and grab the diagnostic code. It's a P0420 code (Cat System efficiency below threshold: Air leak in exhaust before rear HO2S, AF Sensor Error, Fuel System Fault, Faulty Catalytic Converter).
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My check engine light has been coming on and off and it seems to show P0420 for catalytic converter. The light stays off for about a week and it'll come on for a day or two and off again.
Wouldn't a failed converter stay failed? Can P0420 be triggered by loose/bad gas caps?
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I have a 2007 Prius/70,000 miles and live in NY. The Malfunction Indicator Lamp (Check Engine Light) came on back in May when I was visiting Texas and I stopped to have the code read and got a P0420 code - possible emission problem. As I was far from home I took a day to think about what I should do and by the next evening the light had shut off. Driving back to NY the following week the light came on again about 150 miles from home. Once again within a few days it had shut off. End of June I had the same thing happen - this time I took it to a Auto Part store and had them read the codes again. The guy there told me the only thing that showed up was some kind of emission error. Again within a few days the light went off. Just yesterday (August now) the light came on again. I've resisted taking it to the dealer because I know they will charge me $100+ just to plug it in and tell me what I partly already know. I've been reading up the P0420 code online however still have a few questions.
A. Is it normal for this code to go on and off repeatedly without me really doing anything?
B. Is there any way to figure out what the specific issue is without taking it to Toyota?
C. If it is the catalytic converter would I be covered under the Federal Emission Warranty? - which from what I've read is 8 years/80,000 miles?
The following is what the initial code printout read:
Troubleshooting P0420
OEM Brand: Domestic
Definition
Catalyst efficiency low-bank 1
Explanation
The oxygen sensors monitor the Catalytic Converters ability to store oxygen.
Probable cause
1. Catalytic converter defective (failure possibly due to # 2, 3, or 4)
2. Engine misfire or running condition
3. large vacuum leak
4. Engine oil leakage into exhaust-valve guide seals, piston rings
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The power button didn't work for a while: For about two hours, the power button (and other stuff) on my 2007 Prius didn't work. But, after a couple of hours, the button worked again and I was able to power down my car (this after many, many pushes both soft and hard). I've now turned it on and off a few times and the car seems to be OK and it's behaving as if it's smiling at me and saying, "What?"
My questions: Does this happen a "lot"? Would the car have turned off if I turned off the smart function (as described on page 34 of the manual)? Is this issue as serious as it seems? Should I dump the car?
This is the first time in 138K miles that the below issues have manifested separately or together.
Other issues that happened at the same time (this morning when the car didn't turn off) were that the:
Instrument cluster was completely dark except for the check engine light (the dark instrument cluster was what first tipped me off that something was wrong)
Backup camera didn't turn on when I shifted into reverse gear
Phone didn't automatically go to speed dial when I was in motion
Fifth door unlock didn't work; the four doors locked/unlocked using the lock/unlock button on the door, but the hatchback didn't unlock.
A day or so ago, the check engine light came on and is throwing a "P0420" code (I posted about this separately yesterday).
By the way, I found out that if you hold down the power button for a while, the car goes into a different state of being where the ICE isn't running and the battery shows as completely empty.
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I own a 2004 Ford Taurus (3.0L V6, OHV (12), non-flex fuel) registering a P0420 engine code. If I can smell exhaust fumes in the cabin, can I assume there is a leak in the catalytic converter system, or could the O2 sensors be the issue (or could it be the catalytic converter itself...)?
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It was a cold winter in Boston in the last two months. And since then almost every time I started my 2005 Prius, the temperature was default to 75F. Also, the first time I start the car in a day, it almost show the outside temperature as Celsius instead of Fahrenheit unless I press the screen to display something else and then come back, then the Fahrenheit will come back.
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I bought an 04 elantra a few weeks ago. The check engine light is now on and I get code P0420 listed twice with my code reader. I have replaced the downstream O2 sensor and reset the codes only for them to return again. It is my understanding that this is going to be a convertor problem. My question is that from the research I have done it looks as though this car has two converters. One at the exhaust manifold and then another in the tailpipe. Which one is going to be the most likely causing my Check engine light to come on. Or do I need to replace both converters.
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Had the check engine light in the 2005 F150 (90,000 miles) come on. Got the code checked and its P0420. I know that has to do with the cat threshold levels etc. so I believe I am looking to replace the o2 sensor, if I am not mistaken.
How hard of a job is this? Ive done a decent amount of engine work and worked in a shop in high school. Just looking to see if that is the right thing to try first, replacing the sensor, before replacing the cat.
Also I know its the right bank, but if I am not mistaken there is a before and after the cat o2 sensor, which do i replace? Both?
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I recently (about 2 months ago) purchased a '04 Prius with 122k miles on it and it now had 124k. The only problem that it seems to have it a sporadic P0420 cel that come on and off every once in a while (even while on the same tank of gas); I always make sure the gas cap is on tight. On my last fill-up I got about 50mpg, so nothing seems out of the ordinary.
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I was just driving and suddenly i had my CEL pop on. I went to pepboys to have them read the code for me and it Came up P 0420. I have been looking up the code and got a few emissions issues but not sure what one to do first. Any link with Main issues for CEL Codes? Or know what it could be?
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While on business travel, my wife's 2003 1.8T Passat wagon had the MIL illuminate. I had her pull the OBD2 code while I was away, and it came up with P0420. I have been reading up on it, but I have found much in the way of troubleshooting this code. I don't want to just start randomly replacing parts until the light goes away. When I get back I am going to look for exhaust leaks, but barring those what else can be looked for.
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I have the CBFA motor, and i am getting getting the p0420 error code. I have read two related threads here and here about p0420 codes and different downpipes. It seems the AWE and Nuespeed seem to be better for getting around CEL without additional flashes. I currently have purchased and installed one RAI straight O2 spacer (after the cat) and have tried both the medium and smallest insert but after clearing the CEL it has returned both times with the same code. Do i need two O2 spacers, one installed with the smallest insert and another with a different size? Trying to make sense of all the posts.
I am unitronic stage 1, before going stage two i want to have the CEL under control so i can downgrade the flash and not trip CEL for smog.
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I have Unitronics Stage 2, and a 3" downpipe... I keep getting a CEL P0420. I know its about the second o2 sensor, but I don't understand why I am getting the CEL with my chip? Could it be possible that when I put the downpipe back in i reversed the 2 sensors? Or are they the same...
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2006 Toyota Camry LE (4 cyl) with 149,500 miles. All maintenance up to date.
Over the past month, anytime I drive over 80 mph within 15 minutes, the CEL comes on with the code P0420. I read the code and erase it. The funny thing is typically I'm getting very good gas mileage during that tankful when the CEL comes on. I've read that it is likely the downstream oxygen sensor and I plan to replace it. (In February, I replaced the air/fuel sensor). My two questions are:
a) What is the part number for the oxygen sensor (non-California emissions)? I want to make sure I get the right part.
b) Why the CEL comes on after travel over 80 mph? Is this coincidence or is there a reason why this happens?
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Keep getting the P0420 code on this vehicle. Have changed air filter, spark plugs, run fuel injector cleaner through the tank on Shell 93 octane fuel. Drove 430 highway miles to clean out the carbon and the SES light is still on and when we check the code it says Catalyst system effiency below threshold bank 1. How do i get this fixed?
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