PO420.....so now what? - Page 2 - Toyota Yaris Forums

Shroomster · 03-29-2009, 02:55 PM

the sensor should flux between 0-about 1.5 (or up to 3 ) I can't remember correctly but it should flux because of the 4-strokes causing a cyclic reading from around 0 to around 1.5 or 3 and back... if it stays high that means you have still a rich mix or the sensor is damaged, and it if left unattended will eventually burn up the cat. if it hasn't already.

BLAZINBLUEVITZ · 03-29-2009, 03:03 PM

how many miles?

anonymous user · 03-29-2009, 03:42 PM

This code is VERY common on modded cars with OBD2 equipped systems.
Most people don't worry, as it generally means catalyc inefficiency. Hope that's all it means for you. I'd ignore it and keep on driving, and have been on many of my track cars.

la_scanner · 03-29-2009, 04:20 PM

Quote:

Originally Posted by BLAZINBLUEVITZ

how many miles?

around 21, 22,000 miles on vehicle.

la_scanner · 03-29-2009, 04:22 PM

Quote:

Originally Posted by anonymous user

This code is VERY common on modded cars with OBD2 equipped systems.
Most people don't worry, as it generally means catalyc inefficiency. Hope that's all it means for you. I'd ignore it and keep on driving, and have been on many of my track cars.

a couple other people asked me if i have modified or done anything. just a simple yaris here with the most PATHETIC cup holders i have ever seen. so yeah...i had to get that. feels better already.

FunctionSpec · 03-29-2009, 06:32 PM

Air/fuel ratio sensor(AFS B1 S1) voltage should be around 2.8V to 3.8V idling. Stoichiometry is at 3.3V. A voltage of 3.44V means a lean condition (A/f ratio sensor output is the opposite of what happens in a oxygen sensor).

I'm assuming it may be the catalytic converter because of your previous problem. Since you accidentally ran diesel and gas, it didn't burn completely when trying to drive the car which dumped a bunch of raw fuel onto the Cat causing it to overheat and slowly deteriorate. Also some diesel fuel was probably still in the system after draining it plus mixed with higher octane fuel(resists detonation) caused the engine to slowly dump unburned fuel onto the cats. Which is probably why it took awhile for a CEL to come on.

I would test out the O2 sensor(sensor 2) to check for proper operation since it is cheapest to replace and then replace the cat if all sensors check out correctly.

Shroomster · 03-29-2009, 06:40 PM

Quote:

Originally Posted by FunctionSpec

Air/fuel ratio sensor(AFS B1 S1) voltage should be around 2.8V to 3.8V idling. Stoichiometry is at 3.3V. A voltage of 3.44V means a lean condition (A/f ratio sensor output is the opposite of what happens in a oxygen sensor).

hmmm guess I had the lean/rich backwards

la_scanner · 03-29-2009, 07:10 PM

Quote:

Originally Posted by FunctionSpec

Air/fuel ratio sensor(AFS B1 S1) voltage should be around 2.8V to 3.8V idling. Stoichiometry is at 3.3V. A voltage of 3.44V means a lean condition (A/f ratio sensor output is the opposite of what happens in a oxygen sensor).

I'm assuming it may be the catalytic converter because of your previous problem. Since you accidentally ran diesel and gas, it didn't burn completely when trying to drive the car which dumped a bunch of raw fuel onto the Cat causing it to overheat and slowly deteriorate. Also some diesel fuel was probably still in the system after draining it plus mixed with higher octane fuel(resists detonation) caused the engine to slowly dump unburned fuel onto the cats. Which is probably why it took awhile for a CEL to come on.

I would test out the O2 sensor(sensor 2) to check for proper operation since it is cheapest to replace and then replace the cat if all sensors check out correctly.

1/30/09 - fucked up car
1/31/09 - "fixed car" to a a certain extent. LIGHT NOW ON!
2/10/09 - grandma worrying about light on. takes to toyota they say under $1,000
2/11/09 - grandma takes to route 66 tires and auto in glendora. was there for misc crap but he gave her his word spark plugs are fine. LIGHT OFF
3/14/09 - OH SHIT! LIGHT BACK ON! grandma furious

and takes back to route 66 tires and auto in glendora.now he changes mind and says oh yeah, bad bad plugs. replaces them. $138.00. LIGHT OFF NOW
3/16/09 - LIGHT BACK ON!

in meantime im pondering and decide to but innova code reader. and here we are....

la_scanner · 03-29-2009, 07:13 PM

just for anyone who did not see orignal post on here. im sure i'll get in trouble by some on here for re-posting. well, sorry.

Okay, so it was around the end of january when my sister ended up calling home saying car pooped out on freeway. i go and see if i can get it going. i cant.

car gets towed to house. im wondering what it could be. since car turns over. 2 times the car has not started in the past and i had to jump it. finally we got a new battery through toyota. so i knew it wasn't that. in the morning my grandma is asking well now what the hell are we going to do. i have a friend of a friend who is one of those all around do it yourself guys. but he mainly is into cars, racing, etc. i have seen him do many miracles, tricks and what not on old chevys and fords. so im keeping him in the back of my head. i then go out to car again to try and get it going thats when i find the reciet that states $10.22 was filled into car last night. and oh my gosh, what does it say? diesel fuel. almost 5 gallons total. so i call toyota to see what they could do. im debating if i should state that there is diesel fuel in car. well i told them and they say that well that voids the warranty, at least for that repair. so basically $90+ an hour for mechanic. and all these other things he is naming off they would have to do. looking over 5 or $600. okay, no way. thats when i call that guy. he comes over, taste fuel says oh yeah its diesel. we empty all the fuel into a 5 gallon bucket. goes right to the very top. im thinking cool, lets fill it and were done. he says no, spark plugs may be shot. now keep in mind i dont know too much about mechanics of cars. he looks at them says i can try cleaning them i think he said, but then decided no, lets get new ones. there cheap. so we get AUTOLITE Part # XP3924. now we fill with premium fuel. try starting and nothing. he then says lets go back to auto zone. we buy a can of ether. im getting a bit worried, becuase i know my grandma is used to the "normal" or whats normal to her. taking to toyota and paying bucks and thats it. anyway. spraying ether into if i remember correctly the air filter or vent, something like that. intake i forget honestly. that gets it going. something else while thats being done is someone else has the fuel line going to the engine unplugged and is holding it and letting that fuel go into a 1 gallon empty thing of oil. thats when he was pretty certain all the diesel was out of it. car had lots of white smoke coming from the exhaust, it was a bit funny feeling and shaking. but after drive around block a couple times. it was perfect. now is when i notice maitnece light on. engine light or the oil light was already on. i ask him whats up. says its probably because there not toyota plugs in. 2 weeks later grandma decides to take it to toyota to see whats up with it. and they say it will be about 1000 bucks to fix it. she for some reason has no print out of what they were going to do. she took it to local mechanic we have used for years. charges 301 dollars to what he says is a basic tune up. was able to get the yellow maitnece light off and says no, spark plugs are no problem. then a few days later light is back on, says bring it in. now he says oh yes, it is the spark plugs. wrong spark plugs and they should have never have been installed. very bad! $138.00 for install of 4 new toyota brand spark plugs. well guess what, now its a few days later again and YELLOW MAITNENCE LIGHT is back on. so any of you out there who may have the slightest clue even, please....inform me. it would be much appreciated.

FunctionSpec · 03-29-2009, 08:11 PM

MAINTENANCE LIGHT is on? or is the Check Engine light on?

$301 for a basic tune-up at 22k miles? and $138 to change out spark plugs? Sounds like you need a new mechanic. Should of just paid Toyota, you're pretty much halfway there.

la_scanner · 03-29-2009, 09:13 PM

Quote:

Originally Posted by FunctionSpec

MAINTENANCE LIGHT is on? or is the Check Engine light on?

$301 for a basic tune-up at 22k miles? and $138 to change out spark plugs? Sounds like you need a new mechanic. Should of just paid Toyota, you're pretty much halfway there.

301 for tuneup is half true. he also put 2 new yokohama tires on $ 159

BLAZINBLUEVITZ · 03-30-2009, 10:13 AM

Quote:

Originally Posted by la_scanner

around 21, 22,000 miles on vehicle.

its WARRANTY so id take it to dealer......

Loren · 03-30-2009, 10:36 AM

Dealer won't pay a warranty claim because the owner put diesel fuel in a gasoline engine.

However, if you neglect to mention that and just take it in and say "hey, this light came on"... they may find and fix the problem under warranty. (and I agree, it's likely either a fouled catalytic convertor or a fouled O2 sensor caused by trying to burn diesel). I wouldn't take it to the same Toyota dealer that you called and talked to about putting diesel fuel in the tank, though.

Or, you could man up, get your sister to man up, and split the cost of the repair with her. You'd be $300 poorer and DONE with this issue already had you done that. Instead, you're out almost $300 anyway, and still dealing with it.

YarisSedan · 03-30-2009, 11:22 AM

Speaking from experience as a automotive technician. When the computer sets a code P0420 it is comparing the wavelength of the front o2 sensor compared to the rear o2 sensor. When they are simular it detects catalist problems. The most likely cause is your catalic converter isnt operating anymore. Another less likely cause is the o2 sensor heater circuit is defective. But usually this will trigger a o2 sensor code for that. So basically in the morning when the engine is cold the o2 dosnt rapidly heat up and is relying on exhaust gases. One way to test this is disconect the 02 sensors. There should be 4 wires 2 of them the same color usually black. Connect a ohm meter between those 2 wires and you should measure resistance. Usually 12-18 somewhere in that range depending on the temperature. If you measure open loop it means the heater circuit is burnt open. And the 02 needs to be replaced.

If the 02s test okay. You need to be looking at the cat. 2 ways really to test it. One is to get a rubber mallet and tap on the catalitic converter. If you hear rattling like it sounds like tehrs rocks in it. The cat is definately bad. Another way is to get a pyrometer and measure the inlet cat exhaust temp and the outlet cat exhaust temp. The readings after the cat should be hotter. Usually about 100 degrees. If exhaust gas is going in the job of the cat is to flash burn any gasoline that hasnt been fully burn int he combustion chamber. So ofcourse the exhast gas is going to be hotter as it passes through the cat. If the exhaust gas is the same or even cooler. That tells you the cat is doing squat. So it is defective.

If you find out the cat is bad. You now need to trace down the cause. I would suggest looking at your spark plugs. To damage a cat you need to have an excessively rich mixture or incomplete combustion. Otherwise you will have the same problem again.

la_scanner · 04-03-2009, 06:54 PM

okay. i am uploading a youtube video of my grandmother on phone with mechanic. i had called him a half hour before she did. he told me his computer never showed P0420. Since i do not know how to explain what he is talking about. i figured why not listen to it yourself. i should have ready in 10 min.

la_scanner · 04-03-2009, 08:13 PM

http://www.youtube.com/watch?v=rNDyhxXdaf4

Shroomster · 04-03-2009, 09:36 PM

lmao swap the coils?

there are misfire codes that pertain to the specific cylinders (1 through 4) swapping the coils will not make the cat or the 02 sensor work differently.

la_scanner · 04-03-2009, 09:45 PM

Quote:

Originally Posted by Shroomster

lmao swap the coils?

there are misfire codes that pertain to the specific cylinders (1 through 4) swapping the coils will not make the cat or the 02 sensor work differently.

I forgot to add i did call him about a half hour b4 my grandma did and he was saying something about another code that was on for him. i couldn't understand him. but when i told him what im getting off my reader, it's like as if he didn't want to talk about it. maybe im over analyzing this. i can't wait for all the shit from some on here telling me its illegal to record calls. i know, i know. i don't like seeing my grandma get took either.

03-29-2009, 02:55 PM	#19
Shroomster '07 to '12:2 wipers to 1? View User's Garage Drives: '12 5-door LE & '14 5-door LE Join Date: Apr 2007 Location: Orlando Posts: 1,999	the sensor should flux between 0-about 1.5 (or up to 3 ) I can't remember correctly but it should flux because of the 4-strokes causing a cyclic reading from around 0 to around 1.5 or 3 and back... if it stays high that means you have still a rich mix or the sensor is damaged, and it if left unattended will eventually burn up the cat. if it hasn't already. __________________ MicroImageonline forums - Shroomster Xda Forums - Shroomster Androidforums - Shroomster I'm noticing a pattern......

03-29-2009, 03:03 PM	#20
BLAZINBLUEVITZ View User's Garage Drives: 2007 YARIS 3DOOR Join Date: Jan 2009 Location: NEW YORK Posts: 1,275	how many miles? __________________ EVERYBODY EVENTUALLY COMES BACK TO YARISWORLD......

03-30-2009, 10:36 AM	#31
Loren What? Drives: 2007 Yaris LB Join Date: Nov 2008 Location: Safety Harbor, FL Posts: 1,006	Dealer won't pay a warranty claim because the owner put diesel fuel in a gasoline engine. However, if you neglect to mention that and just take it in and say "hey, this light came on"... they may find and fix the problem under warranty. (and I agree, it's likely either a fouled catalytic convertor or a fouled O2 sensor caused by trying to burn diesel). I wouldn't take it to the same Toyota dealer that you called and talked to about putting diesel fuel in the tank, though. Or, you could man up, get your sister to man up, and split the cost of the repair with her. You'd be $300 poorer and DONE with this issue already had you done that. Instead, you're out almost $300 anyway, and still dealing with it. __________________ ----------------------- Loren@InvisibleSun.org -----------------------

03-30-2009, 11:22 AM	#32
YarisSedan Drives: 08 Yaris Sedan Join Date: Oct 2008 Location: California - Bay Area Posts: 2,773	Speaking from experience as a automotive technician. When the computer sets a code P0420 it is comparing the wavelength of the front o2 sensor compared to the rear o2 sensor. When they are simular it detects catalist problems. The most likely cause is your catalic converter isnt operating anymore. Another less likely cause is the o2 sensor heater circuit is defective. But usually this will trigger a o2 sensor code for that. So basically in the morning when the engine is cold the o2 dosnt rapidly heat up and is relying on exhaust gases. One way to test this is disconect the 02 sensors. There should be 4 wires 2 of them the same color usually black. Connect a ohm meter between those 2 wires and you should measure resistance. Usually 12-18 somewhere in that range depending on the temperature. If you measure open loop it means the heater circuit is burnt open. And the 02 needs to be replaced. If the 02s test okay. You need to be looking at the cat. 2 ways really to test it. One is to get a rubber mallet and tap on the catalitic converter. If you hear rattling like it sounds like tehrs rocks in it. The cat is definately bad. Another way is to get a pyrometer and measure the inlet cat exhaust temp and the outlet cat exhaust temp. The readings after the cat should be hotter. Usually about 100 degrees. If exhaust gas is going in the job of the cat is to flash burn any gasoline that hasnt been fully burn int he combustion chamber. So ofcourse the exhast gas is going to be hotter as it passes through the cat. If the exhaust gas is the same or even cooler. That tells you the cat is doing squat. So it is defective. If you find out the cat is bad. You now need to trace down the cause. I would suggest looking at your spark plugs. To damage a cat you need to have an excessively rich mixture or incomplete combustion. Otherwise you will have the same problem again. __________________ http://www.cardomain.com/ride/3210549

04-03-2009, 09:36 PM	#35
Shroomster '07 to '12:2 wipers to 1? View User's Garage Drives: '12 5-door LE & '14 5-door LE Join Date: Apr 2007 Location: Orlando Posts: 1,999	lmao swap the coils? there are misfire codes that pertain to the specific cylinders (1 through 4) swapping the coils will not make the cat or the 02 sensor work differently. __________________ MicroImageonline forums - Shroomster Xda Forums - Shroomster Androidforums - Shroomster I'm noticing a pattern......

03-29-2009, 03:42 PM	#21
anonymous user rarer than JDM -1 of 1! View User's Garage Drives: 07yaris Join Date: Oct 2008 Location: windward oahu Posts: 402	This code is VERY common on modded cars with OBD2 equipped systems. Most people don't worry, as it generally means catalyc inefficiency. Hope that's all it means for you. I'd ignore it and keep on driving, and have been on many of my track cars.

03-29-2009, 06:32 PM	#24
FunctionSpec Super Newbie View User's Garage Drives: 2007 Yaris Liftback White Join Date: Jul 2007 Location: 626, Southern California Posts: 180	Air/fuel ratio sensor(AFS B1 S1) voltage should be around 2.8V to 3.8V idling. Stoichiometry is at 3.3V. A voltage of 3.44V means a lean condition (A/f ratio sensor output is the opposite of what happens in a oxygen sensor). I'm assuming it may be the catalytic converter because of your previous problem. Since you accidentally ran diesel and gas, it didn't burn completely when trying to drive the car which dumped a bunch of raw fuel onto the Cat causing it to overheat and slowly deteriorate. Also some diesel fuel was probably still in the system after draining it plus mixed with higher octane fuel(resists detonation) caused the engine to slowly dump unburned fuel onto the cats. Which is probably why it took awhile for a CEL to come on. I would test out the O2 sensor(sensor 2) to check for proper operation since it is cheapest to replace and then replace the cat if all sensors check out correctly.

03-29-2009, 07:13 PM	#27
la_scanner Drives: 2007 toyota yaris Join Date: Mar 2009 Location: southern california Posts: 87	just for anyone who did not see orignal post on here. im sure i'll get in trouble by some on here for re-posting. well, sorry. Okay, so it was around the end of january when my sister ended up calling home saying car pooped out on freeway. i go and see if i can get it going. i cant. car gets towed to house. im wondering what it could be. since car turns over. 2 times the car has not started in the past and i had to jump it. finally we got a new battery through toyota. so i knew it wasn't that. in the morning my grandma is asking well now what the hell are we going to do. i have a friend of a friend who is one of those all around do it yourself guys. but he mainly is into cars, racing, etc. i have seen him do many miracles, tricks and what not on old chevys and fords. so im keeping him in the back of my head. i then go out to car again to try and get it going thats when i find the reciet that states $10.22 was filled into car last night. and oh my gosh, what does it say? diesel fuel. almost 5 gallons total. so i call toyota to see what they could do. im debating if i should state that there is diesel fuel in car. well i told them and they say that well that voids the warranty, at least for that repair. so basically $90+ an hour for mechanic. and all these other things he is naming off they would have to do. looking over 5 or $600. okay, no way. thats when i call that guy. he comes over, taste fuel says oh yeah its diesel. we empty all the fuel into a 5 gallon bucket. goes right to the very top. im thinking cool, lets fill it and were done. he says no, spark plugs may be shot. now keep in mind i dont know too much about mechanics of cars. he looks at them says i can try cleaning them i think he said, but then decided no, lets get new ones. there cheap. so we get AUTOLITE Part # XP3924. now we fill with premium fuel. try starting and nothing. he then says lets go back to auto zone. we buy a can of ether. im getting a bit worried, becuase i know my grandma is used to the "normal" or whats normal to her. taking to toyota and paying bucks and thats it. anyway. spraying ether into if i remember correctly the air filter or vent, something like that. intake i forget honestly. that gets it going. something else while thats being done is someone else has the fuel line going to the engine unplugged and is holding it and letting that fuel go into a 1 gallon empty thing of oil. thats when he was pretty certain all the diesel was out of it. car had lots of white smoke coming from the exhaust, it was a bit funny feeling and shaking. but after drive around block a couple times. it was perfect. now is when i notice maitnece light on. engine light or the oil light was already on. i ask him whats up. says its probably because there not toyota plugs in. 2 weeks later grandma decides to take it to toyota to see whats up with it. and they say it will be about 1000 bucks to fix it. she for some reason has no print out of what they were going to do. she took it to local mechanic we have used for years. charges 301 dollars to what he says is a basic tune up. was able to get the yellow maitnece light off and says no, spark plugs are no problem. then a few days later light is back on, says bring it in. now he says oh yes, it is the spark plugs. wrong spark plugs and they should have never have been installed. very bad! $138.00 for install of 4 new toyota brand spark plugs. well guess what, now its a few days later again and YELLOW MAITNENCE LIGHT is back on. so any of you out there who may have the slightest clue even, please....inform me. it would be much appreciated.

03-29-2009, 08:11 PM	#28
FunctionSpec Super Newbie View User's Garage Drives: 2007 Yaris Liftback White Join Date: Jul 2007 Location: 626, Southern California Posts: 180	MAINTENANCE LIGHT is on? or is the Check Engine light on? $301 for a basic tune-up at 22k miles? and $138 to change out spark plugs? Sounds like you need a new mechanic. Should of just paid Toyota, you're pretty much halfway there.

04-03-2009, 06:54 PM	#33
la_scanner Drives: 2007 toyota yaris Join Date: Mar 2009 Location: southern california Posts: 87	okay. i am uploading a youtube video of my grandmother on phone with mechanic. i had called him a half hour before she did. he told me his computer never showed P0420. Since i do not know how to explain what he is talking about. i figured why not listen to it yourself. i should have ready in 10 min.

04-03-2009, 08:13 PM	#34
la_scanner Drives: 2007 toyota yaris Join Date: Mar 2009 Location: southern california Posts: 87	http://www.youtube.com/watch?v=rNDyhxXdaf4