 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
Car Forum / Lexus Cars / August 2007P0420 code
This code was noted as 'BANK 1 CATALYST EFFICIENCY'. My local Lexus specialist quoted me $2610.08 for front bank 1 and rear catalytic converters. If the code refers to bank 1 why would I have to replace the rear converter? Does this seem like a fair quote? 2002 Lexus GS300. my local mechanic told me code p0420 was the converter-he said that code was a converter failure. this was on 99 Accord. however, the check engine light has since disappeared. This code was noted as 'BANK 1 CATALYST EFFICIENCY'. My local Lexus specialist quoted me $2610.08 for front bank 1 and rear catalytic converters. If the code refers to bank 1 why would I have to replace the rear converter? Does this seem like a fair quote? 2002 Lexus GS300. > This code was noted as 'BANK 1 CATALYST EFFICIENCY'. My local Lexus > specialist quoted me $2610.08 for front bank 1 and rear catalytic [quoted text clipped - 3 lines] > 2002 Lexus GS300. >How can does this part fail on a 5 year old car BTW. > This code was noted as 'BANK 1 CATALYST EFFICIENCY'. My local Lexus > specialist quoted me $2610.08 for front bank 1 and rear catalytic > converters. If the code refers to bank 1 why would I have to replace the > rear converter? Does this seem like a fair quote? > > 2002 Lexus GS300. "Bank 1" refers to the cylinder bank that contains Cylinder #1. In the case of an in-line engine, there is no Bank 2; only Bank 1. I'm pretty sure that your car has only 1 catalytic converter but it has two O2 sensors - 1 before the converter and 1 after the converter. The dealer is probably replacing the catalytic converter and both O2 sensors for that price. The catalytic converter failure may be covered by the 8 year, 80,000 miles emissions performance warranty although you may have to pay for the O2 sensors. Ask your service department about emissions warranty coverage.  SignatureRay O (correct punctuation to reply) >> This code was noted as 'BANK 1 CATALYST EFFICIENCY'. My local Lexus >> specialist quoted me $2610.08 for front bank 1 and rear catalytic [quoted text clipped - 13 lines] > emissions performance warranty although you may have to pay for the O2 > sensors. Ask your service department about emissions warranty coverage. Does this mean I may only need to replace the O2 sensors and not the catalytic converter. Wouldn't this be a less expensive option to try before replacing the converter? >>> This code was noted as 'BANK 1 CATALYST EFFICIENCY'. My local Lexus >>> specialist quoted me $2610.08 for front bank 1 and rear catalytic [quoted text clipped - 18 lines] > catalytic converter. Wouldn't this be a less expensive option to try > before replacing the converter? The proper diagnostic procedure is to CHECK both O2 sensors to see if they are functioning properly before replacing the catalytic converter. If they appear to be functioning properly, then the catalytic converter is suspect, and the dealer is probably replacing both O2 sensors to make sure the car doesn't come back with the same trouble code. SignatureRay O (correct punctuation to reply) >>>> This code was noted as 'BANK 1 CATALYST EFFICIENCY'. My local Lexus >>>> specialist quoted me $2610.08 for front bank 1 and rear catalytic [quoted text clipped - 24 lines] > suspect, and the dealer is probably replacing both O2 sensors to make sure > the car doesn't come back with the same trouble code. The dealer never said anything about the sensors. They just checked the code and said it was a catalytic converter and quoted 2600.00. I just sent the owner of the shop a e-mail requesting a quote for the O2 sensors. I think I may get a second opinion. There is new shop across the street from my normal shop. >>>>> This code was noted as 'BANK 1 CATALYST EFFICIENCY'. My local Lexus >>>>> specialist quoted me $2610.08 for front bank 1 and rear catalytic [quoted text clipped - 30 lines] > think I may get a second opinion. There is new shop across the street from > my normal shop. How many miles on the car? SignatureRay O (correct punctuation to reply) >>>>>> This code was noted as 'BANK 1 CATALYST EFFICIENCY'. My local Lexus >>>>>> specialist quoted me $2610.08 for front bank 1 and rear catalytic [quoted text clipped - 32 lines] >>> > How many miles on the car? The car has 115K. >>>>>>> This code was noted as 'BANK 1 CATALYST EFFICIENCY'. My local Lexus >>>>>>> specialist quoted me $2610.08 for front bank 1 and rear catalytic [quoted text clipped - 34 lines] > > The car has 115K. <snipped> >>>>> Does this mean I may only need to replace the O2 sensors and not the >>>>> catalytic converter. Wouldn't this be a less expensive option to try [quoted text clipped - 15 lines] > > The car has 115K. Sorry, you're out of luck on the emissions warranty. If you want to invest in a volt/ohm meter, you can check out the O2 sensors yourself and see if they are working properly or not. SignatureRay O (correct punctuation to reply) [SNIP] >Sorry, you're out of luck on the emissions warranty. If you want to invest >in a volt/ohm meter, you can check out the O2 sensors yourself and see if >they are working properly or not. What should the readings be? SignatureJay (remove dashes for legal email address) > [SNIP] >> [quoted text clipped - 4 lines] > > What should the readings be? Here is a pretty good explanation of how O2 sensors work and what the voltages should be: http://www.aa1car.com/library/o2sensor.htm SignatureRay O (correct punctuation to reply) >> [SNIP] >>> [quoted text clipped - 8 lines] > voltages should be: > http://www.aa1car.com/library/o2sensor.htm Great article-- thanks Ray. I have a 1992 SC400 with 190K miles. The O2 sensor has never been replaced but I have no symptoms mentioned in article. Should I consider to replace as preventative measure? Appreciate your prolific feedback to this forum. >>> [SNIP] >>>> [quoted text clipped - 15 lines] > > Appreciate your prolific feedback to this forum. If it were my car, I wouldn't worry about it, but if you want, you can measure O2 sensor voltage and replace if it is only barely within specs. SignatureRay O (correct punctuation to reply) >> [SNIP] >>> [quoted text clipped - 8 lines] >voltages should be: >http://www.aa1car.com/library/o2sensor.htm Thanks -- good reference! SignatureJay (remove dashes for legal email address) >>> [SNIP] >>>> [quoted text clipped - 11 lines] > > Thanks -- good reference! You're welcome! SignatureRay O (correct punctuation to reply) >>>> [SNIP] >>>>> [quoted text clipped - 13 lines] > > You're welcome! P0420 is usually reliable (sorry.) O2 Sensors have to respond reliably and consistently to their tests to set this. cyl 1, 2, 3 => B1 cyl 4, 5, 6 => B2 Look for aftermarket cat. ... they exist. >>>>> [SNIP] >>>>>> [quoted text clipped - 18 lines] > O2 Sensors have to respond reliably and consistently to their tests to set > this. I'm not sure what you mean by a "reliable' code. If you check the factory service manual, you will see the the first step in diagnosing this code is to check the O2 sensors first. > cyl 1, 2, 3 => B1 > cyl 4, 5, 6 => B2 The OP's car has an in-line configuration - there is no bank 2. > Look for aftermarket cat. ... they exist. SignatureRay O (correct punctuation to reply) The dealer is supposed to check for: 1. Make sure the engine is well tuned. If the ignition system is putting out too much hydrocarbon it will degrade the converters. 2. Check for false air entries in the exhaust system. This can throw off the oxygen sensors. 3. Oxygen sensors themselves. This is almost impossible as the sensors can be marginal or even fail and they won't set codes. Being wear items, I would replace the sensors. In fact, I've fixed a P0420 problem by junking the Denso sensors and using the Bosch Planar type oxygen sensor. Bosch planars are best-in-class. http://www.boschautoparts.com/Products/OxygenSensors/PlanarO2.htm If you can get Bosch planars for your car, go for them. And stay away from Densos. 3. Then you should consider changing out the converters. Converters are substrates coated with platinum. Unless they crumble you should be fine. $2600. Sheeeeeesh. > The dealer never said anything about the sensors. They just checked the code > and said it was a catalytic converter and quoted 2600.00. I just sent the > owner of the shop a e-mail requesting a quote for the O2 sensors. I think I > may get a second opinion. There is new shop across the street from my normal > shop. > The dealer is supposed to check for: > [quoted text clipped - 3 lines] > 2. Check for false air entries in the exhaust system. This can throw > off the oxygen sensors. Air entering the exhaust system will probably set DTC P0125 - insufficient coolant temperature for closed loop operation. > 3. Oxygen sensors themselves. This is almost impossible as the sensors > can be marginal or even fail and they won't set codes. Checking the oxygen sensors themselves is very easy with a volt meter or OBD II scan tool with the capability to display raw sensor output values. Being wear > items, I would replace the sensors. I recommend checking components before replacing them, even if they are wear items. For example, people would not be happy if a shop replaced brakes or tires without first checking their condition to see if they need replacement. In fact, I've fixed a P0420 > problem by junking the Denso sensors and using the Bosch Planar type > oxygen sensor. Bosch planars are best-in-class. [quoted text clipped - 3 lines] > If you can get Bosch planars for your car, go for them. And stay away > from Densos. > 3. Then you should consider changing out the converters. Converters > are substrates coated with platinum. Unless they crumble you should be > fine. If the catalyst becomes coated with particulate matter, the exhaust gas does not come in contact with the catalyst and so the catalyst doesn't do anything. SignatureRay O (correct punctuation to reply) > Air entering the exhaust system will probably set DTC P0125 - insufficient > coolant temperature for closed loop operation. False air entry into the exhaust is usually seen as a lean condition (excess presence of oxygen) and will cause ECU to command more fuel. Why would it set P0125? > Checking the oxygen sensors themselves is very easy with a volt meter or OBD > II scan tool with the capability to display raw sensor output values. I've seen sensor waveforms. I'd think the reaction time waveform need to correlate with fuel to diagnose slow sensor (and not dead sensors), which is the problem with many P0420 codes. I've seen people done it using oscilloscopes with snap-throttle tests, but not sure about the OBD-II data frames, so I'll leave it to the experts here. "...while a dead sensor can be detected with a relatively inexpensive digital volt-ohmmeter, a slow sensor can only be diagnosed by a more expensive oscilloscope or scope meter." - Bosch USA > I recommend checking components before replacing them, even if they are wear > items. For example, people would not be happy if a shop replaced brakes or > tires without first checking their condition to see if they need > replacement. Agreed. That why cars need to be well tuned, which is the #1 thing I mentioned techs should check. But unfortunately, this Toyota (Lexus) tech didn't even do that, recommending converter changed just based on a P0420. That's too bad. > If the catalyst becomes coated with particulate matter, the exhaust gas does > not come in contact with the catalyst and so the catalyst doesn't do > anything. Yup, that's why it's so important to keep the engines well tuned!! > Ray O > (correct punctuation to reply) >> Air entering the exhaust system will probably set DTC P0125 - >> insufficient [quoted text clipped - 3 lines] > (excess presence of oxygen) and will cause ECU to command more fuel. > Why would it set P0125? Yes, air entering the exhaust will make the exhaust seem lean, and I don't know why the ECU sets P0125. For some reason, the factory repair manual does say to check for an exhaust leak if P0125 comes up, and I have seen this code caused by exhaust leaks, usually from a loose O2 sensor. >> Checking the oxygen sensors themselves is very easy with a volt meter or >> OBD [quoted text clipped - 10 lines] > expensive oscilloscope or scope meter." > - Bosch USA A higher end OBD II scanner can compare O2 sensor output. To set P0420, the ECU compares the signals from the #1 and #2 sensors. When they are working properly, #1 sensor should have both higher frequency and higher amplitude than sensor #2 because if the cat is working, sensor #2 shouldn't see as much activity. If the signal from sensor #2 looks like the signal from sensor #1, the ECU assumes that the cat isn't working and sets P0420. If sensor #1 is marginal and not reacting quickly enough, its signal starts to look like the signal from sensor #2, and if the signals look alike, it will set the code. >> I recommend checking components before replacing them, even if they are >> wear [quoted text clipped - 7 lines] > tech didn't even do that, recommending converter changed just based on > a P0420. That's too bad. I don't know whether or not the tech checked the signals from the sensor, and if the sensors were working properly, then the cat is bad. If the tech checked the sensors, then he should have noted that on the repair order, although this is not always done. If the tech did not check the sensors, then that is incomplete or lazy diagnosis. >> If the catalyst becomes coated with particulate matter, the exhaust gas >> does >> not come in contact with the catalyst and so the catalyst doesn't do >> anything. > > Yup, that's why it's so important to keep the engines well tuned!! I agree, engines should be kept well tuned. Fortunately, modern engines require very little tuning. Unfortunately, owners often neglect the engines since there is so little to do. SignatureRay O (correct punctuation to reply) Yeah. People have said the diagnostics codes are often wrong and one has to make sure the root of the problem by additional tests. Toyota's setting P0125 for false air entry and how P0420 sometimes mis-dignoses the catalytic converter problem are good examples. > > False air entry into the exhaust is usually seen as a lean condition > > (excess presence of oxygen) and will cause ECU to command more fuel. [quoted text clipped - 4 lines] > does say to check for an exhaust leak if P0125 comes up, and I have seen > this code caused by exhaust leaks, usually from a loose O2 sensor. ... > A higher end OBD II scanner can compare O2 sensor output. To set P0420, > the ECU compares the signals from the #1 and #2 sensors. When they are [quoted text clipped - 5 lines] > to look like the signal from sensor #2, and if the signals look alike, it > will set the code. > Yeah. People have said the diagnostics codes are often wrong and one > has to make sure the root of the problem by additional tests. Toyota's > setting P0125 for false air entry and how P0420 sometimes mis-dignoses > the catalytic converter problem are good examples. It is not that the codes are wrong, I'd say it is more like the descriptions are not intuitive. The standard codes and the parameter that set them are determined by the SAE, not the individual automakers. SignatureRay O (correct punctuation to reply) Yeah, you know, with all the infamous Toyota/Lexus idle air control valve failures (so much that Toyota gave out free valves but charged labor -- an arm and a leg), in all cases the ECUs didn't set the P0505 code like it's supposed to. On Aug 18, 11:17 pm, "Ray O" <rokigawaATtristarassociatesDOTcom> wrote: > It is not that the codes are wrong, I'd say it is more like the descriptions > are not intuitive. The standard codes and the parameter that set them are [quoted text clipped - 3 lines] > Ray O > (correct punctuation to reply) > Yeah, you know, with all the infamous Toyota/Lexus idle air control > valve failures (so much that Toyota gave out free valves but charged > labor -- an arm and a leg), in all cases the ECUs didn't set the P0505 > code like it's supposed to. A P0505 would be set if there was an open or short in the idle air control valve circuit. The ECU has no way of knowing if the IAC is gummed up or not moving enough. The primary purpose of the OBD II system is to identify if a system that will affect emissions is malfunctioning. Two common misconception are that the OBD II system identify every problem with a vehicle, including ones that affect driveability, and that the component named in the diagnostic trouble code description must be bad if the code names the component. Unfortunately, those misconceptions lead people who may be familiar with older automotive systems but who have not studied the principles behind automotive on board diagnostic systems to give misguided advice. SignatureRay O (correct punctuation to reply) > On Aug 18, 11:17 pm, "Ray O" <rokigawaATtristarassociatesDOTcom> > wrote: [quoted text clipped - 7 lines] >> Ray O >> (correct punctuation to reply) I've cleaned other manufactorer's IAC without a short circuit that was gummed up and set P0505 like it's supposed to. I guess some ECUs are not as smart as others in being able to checking engine RPMs changes while commanding IACs. On Aug 19, 10:48 pm, "Ray O" <rokigawaATtristarassociatesDOTcom> wrote: > A P0505 would be set if there was an open or short in the idle air control > valve circuit. The ECU has no way of knowing if the IAC is gummed up or not [quoted text clipped - 8 lines] > older automotive systems but who have not studied the principles behind > automotive on board diagnostic systems to give misguided advice. > I've cleaned other manufactorer's IAC without a short circuit that was > gummed up and set P0505 like it's supposed to. I guess some ECUs are > not as smart as others in being able to checking engine RPMs changes > while commanding IACs. I guess not! SignatureRay O (correct punctuation to reply) No, that's not correct. Some manufacturers measure P0420 with oxygen store test and some with pre/post sensor waveform test. Conditions under which tests are run can vary greatly between manufacturers. On Aug 18, 11:17 pm, "Ray O" <rokigawaATtristarassociatesDOTcom> wrote: > It is not that the codes are wrong, I'd say it is more like the descriptions > are not intuitive. The standard codes and the parameter that set them are [quoted text clipped - 3 lines] > Ray O > (correct punctuation to reply) > No, that's not correct. Some manufacturers measure P0420 with oxygen > store test and some with pre/post sensor waveform test. Conditions > under which tests are run can vary greatly between manufacturers. I think we're discussing a difference in semantics. Yes, the conditions under which tests are run can vary greatly between manufacturers, however, the code number, description, and parameters are set by the SAE. For P0420, the **parameter** that sets the code is a bad catalytic converter, and as you pointed out, there is more than one way to determine whether the parameter is met or not. SignatureRay O (correct punctuation to reply) |
Reply to this Message |
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2008 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.