Check Engine Light

[khmerxrom3o]

Hi, I'm have a problem with my IS 300, I took it to Advance Auto Parts and did a DIAG. test and it gave me a reading.

P0420

P0430

P0420P/D

Bank 1 and Bank 2. Catalyst Eff. below threshold... ANy help would be helpful. Thank you

[smooth1]

Well, the ODB II codes you have there are pretty self explanatory. What did you need help with?

[Shoaib]

Well, the ODB II codes you have there are pretty self explanatory. What did you need help with?

self explanatory to you smooth :-( that looks like French to me and i believe the OP is looking for help in deciphering those codes. I'm kinda guessing they have something to do with the O2 sensors because of the bank 1 and 2 thing. But, I'm sure I'm prolly wrong.

[djspawn00]

What year and mileage is your car??? I think you may need a new catalytic converter... I'd say disconnect the battery to reset the check engine light. See if they come back on, if they do pull the codes again and then go from there. A new catalytic converter can be pricey... anywhere here is the generic info on those codes...

P0420 OBD-II Trouble Code

Technical DescriptionCatalyst System Efficiency Below Threshold (Bank 1)

What does that mean?Basically this means that the oxygen sensor downstream (after) the catalytic converter on bank 1 is detecting that the converter is not working as efficiently as it should be (according to specs). It is part of the vehicle emissions system.

SymptomsYou will likely not notice any drivability problems, although there may be symptoms.

CausesA code P0420 may mean that one or more of the following has happened:

Leaded fuel was used where unleaded was called for

An oxygen sensor is not reading (functioning) properly

The engine coolant temperature sensor is not working properly

Damaged exhaust manifold / catalytic converter / exhaust pipe

Retarded spark timing

Possible SolutionsThe simplest thing to do is to reset the code and see if it comes back.

Next step is to measure the voltage at the oxygen sensor on Bank 1 (the rear sensor, or the sensor after the converter). The voltage should be low and steady (~200mV, depends on the vehicle). If the voltage varies (e.g. 100mV to 600mV) then it's time to replace the catalytic converter. In fact, it would be a good idea to test each oxygen O2 sensor while you're at it.

One thing to note is that many vehicle manufacturers offer a longer warranty on emissions-related parts. So if you have a newer car but it's out of it's bumper-to-bumper warranty, there still may be warranty on this type of problem. Many manufacturers give a five year, unlimited mileage warranty on these items. It's worth checking into.

P0430 OBD-II Trouble Code

Technical DescriptionCatalyst System Efficiency Below Threshold (Bank 2)

What does that mean?Basically this means that the oxygen sensor downstream of the catalytic converter on bank 2 (passenger side) is detecting that the converter is not working as efficiently as it should be (according to specs). It is part of the vehicle emissions system.

SymptomsYou will likely not notice any drivability problems, although there may be symptoms such as a rough/hard idle when cold.

CausesA code P0430 may mean that one or more of the following has happened:

The catalytic converter is no longer functioning properly

An oxygen sensor is not reading (functioning) properly

There is an exhaust leak

Possible SolutionsThe simplest thing to do is to reset the code and see if it comes back.

Then inspect for exhaust leaks.

Next step is to measure the voltage at the oxygen sensor on Bank 2 (the passenger side rear sensor, or the sensor after the converter). The voltage should be low and steady (~200mV, depends on the vehicle). If the voltage varies (e.g. 100mV to 600mV) then it's time to replace the catalytic converter. In fact, it would be a good idea to test each oxygen O2 sensor while you're at it.

One thing to note is that many vehicle manufacturers offer a longer warranty on emissions-related parts. So if you have a newer car but it's out of it's bumper-to-bumper warranty, there still may be warranty on this type of problem. Many manufacturers give a five year, unlimited mileage warranty on these items. It's worth checking into.

[khmerxrom3o]

i installed headers and an exhuast and 2 weeks later the check engine light came on. it's 2001 and it has about 85k miles on it. how much would an cat cost me?

[smooth1]

So, you have deleted the catalysts then. You will need to change them out to 02 simulators. You will probably need to add a spacer to the rear sensor as well, but that may be only if you keep having this issue after you change to the 02 sims, because you don't have those cats there anymore.

[khmerxrom3o]

no the cat is still there. i just had to replace the o2 on them. now i'm trying to install an air fuel gauge and afc on my car because i think im running too rich. any ideas?

[smooth1]

If you installed a header, you don't have the 3 way catalysts on bank 1 and 2 anymore. As those were part of header you replaced. In the new header, they would have drilled and welded the new bongs for the 02 sensors. After that, you usually end up having to swap those to sims as the new temp and flow readings will be outside the parameters set in the ECU. You do still have the catalytic converter on the down pipe, as most exhaust systems are cat back from there. So the sensor after that cat should still be ok to leave.

Your running rich is a compenstion. Once you fix the cel's, it should get better. You may need to do a full ECU reset though. But you can determine that later.

[khmerxrom3o]

how do you do a full ECU reset?

[bartkat]

Just disconnect the negative battery terminal for 10 minutes and then reconnect. Then start the engine, let idle for 5 or so minutes.

[khmerxrom3o]

ok. i got a question i was wondering where do i find the o2 sensor signal? im trying to add a air fuel gauge and i need help findind it.

[smooth1]

PM answered.

[larful]

What year and mileage is your car??? I think you may need a new catalytic converter... I'd say disconnect the battery to reset the check engine light. See if they come back on, if they do pull the codes again and then go from there. A new catalytic converter can be pricey... anywhere here is the generic info on those codes...

Technical DescriptionCatalyst System Efficiency Below Threshold (Bank 1)

What does that mean?Basically this means that the oxygen sensor downstream (after) the catalytic converter on bank 1 is detecting that the converter is not working as efficiently as it should be (according to specs). It is part of the vehicle emissions system.

SymptomsYou will likely not notice any drivability problems, although there may be symptoms.

CausesA code P0420 may mean that one or more of the following has happened:

Leaded fuel was used where unleaded was called for

An oxygen sensor is not reading (functioning) properly

The engine coolant temperature sensor is not working properly

Damaged exhaust manifold / catalytic converter / exhaust pipe

Retarded spark timing

Possible SolutionsThe simplest thing to do is to reset the code and see if it comes back.

Next step is to measure the voltage at the oxygen sensor on Bank 1 (the rear sensor, or the sensor after the converter). The voltage should be low and steady (~200mV, depends on the vehicle). If the voltage varies (e.g. 100mV to 600mV) then it's time to replace the catalytic converter. In fact, it would be a good idea to test each oxygen O2 sensor while you're at it.

One thing to note is that many vehicle manufacturers offer a longer warranty on emissions-related parts. So if you have a newer car but it's out of it's bumper-to-bumper warranty, there still may be warranty on this type of problem. Many manufacturers give a five year, unlimited mileage warranty on these items. It's worth checking into.

P0430 OBD-II Trouble Code

Technical DescriptionCatalyst System Efficiency Below Threshold (Bank 2)

What does that mean?Basically this means that the oxygen sensor downstream of the catalytic converter on bank 2 (passenger side) is detecting that the converter is not working as efficiently as it should be (according to specs). It is part of the vehicle emissions system.

SymptomsYou will likely not notice any drivability problems, although there may be symptoms such as a rough/hard idle when cold.

CausesA code P0430 may mean that one or more of the following has happened:

The catalytic converter is no longer functioning properly

An oxygen sensor is not reading (functioning) properly

There is an exhaust leak

Possible SolutionsThe simplest thing to do is to reset the code and see if it comes back.

Then inspect for exhaust leaks.

Next step is to measure the voltage at the oxygen sensor on Bank 2 (the passenger side rear sensor, or the sensor after the converter). The voltage should be low and steady (~200mV, depends on the vehicle). If the voltage varies (e.g. 100mV to 600mV) then it's time to replace the catalytic converter. In fact, it would be a good idea to test each oxygen O2 sensor while you're at it.

One thing to note is that many vehicle manufacturers offer a longer warranty on emissions-related parts. So if you have a newer car but it's out of it's bumper-to-bumper warranty, there still may be warranty on this type of problem. Many manufacturers give a five year, unlimited mileage warranty on these items. It's worth checking into.

Im having this same code come up for my engine check light, in my 2002 lexus IS300 , I reset the battery and it hasnt popped back up yet so Im waiting for it right now what is the next step then the O2 sensor? how do you pinpoint what is the cause of the engine check light if the only code thrown is P0420 trouble code

[vcCUZ]

Hi, I'm have a problem with my IS 300, I took it to Advance Auto Parts and did a DIAG. test and it gave me a reading.

P0420

P0430

P0420P/D

Bank 1 and Bank 2. Catalyst Eff. below threshold... ANy help would be helpful. Thank you

Yea i threw a MIL too but it was p0161 o2 sensor heater circuit malfunction bnk 2 sensor 2 basically my o2 needs replacing. I believe your cats are out a good test is to get under there and hit it with a rubber mallet and listen to any rattling which there isnt supposed to be.

[smooth1]

Hi, I'm have a problem with my IS 300, I took it to Advance Auto Parts and did a DIAG. test and it gave me a reading.

P0420

P0430

P0420P/D

Bank 1 and Bank 2. Catalyst Eff. below threshold... ANy help would be helpful. Thank you

Yea i threw a MIL too but it was p0161 o2 sensor heater circuit malfunction bnk 2 sensor 2 basically my o2 needs replacing. I believe your cats are out a good test is to get under there and hit it with a rubber mallet and listen to any rattling which there isnt supposed to be.

Just make sure you stick with Denso. Bosch 02's for some reason don't work very well in Toyota/Lexus, or most imports for that matter. But yeah, that is the more common code I see alot. The sensor is around 60 bucks. It's easy enouph to replace as it's the one that's further back near the passenger seat.