Hello team,
My name is Josh and have followed IH8MUD since high school when I got a '90 FJ62. Recently got into a 100 series though, so thanks for being here!
I've seen a few threads about threshold error codes with multitudes of suggested fixes, bypasses, and hacks. So I apologize for any duplication, however, most of those threads tend to end in a lack of resolution, or people working around solutions. My goal is ultimately to diagnose the actual cause and fix it properly. My ask is for a greater understanding of the system affected by the error codes and steps, tips, guide, etc. for diagnosing the potential issues and the solutions.
I appreciate any help in advance!
2004 Lexus LX-470 in April.
2 Owners. Driven in Louisiana and NC.
250,000 Miles and came with a stack of maintenance receipts (mostly oil changes).
Purchased in Charlotte, NC and drove to Charleston, SC.
Of course CEL, VSC Trac, and VSC OFF lights came on second day I got it when driving around town. It has since taken me coast to coast with no issues like a champ.
In general when on the highway the lights will go off, and when driving in the city they come back on. Doesn't run rough, but there is a strong smell from the exhaust sometimes.
Maintenance I've done unrelated to trying to fix these codes:
-New radiator and hoses.
-New battery.
-Changed oil & filter.
Trouble Codes:
P0420 (Bank 1) Sensor 2 Below threshold
P0430 (Bank 2) Sensor 2 Below threshold
Therefore, from my understanding:
The down stream sensors on both sides are reading too low of values with main potential causes being a bad catalytic converter, bad 02 sensors, or a leak in the exhaust.
Anyone know the best route to start ruling things out?
Current next steps are to 1. Plug the OBDII reader back in and try to check flow rate of upstream 02 sensors and compare to downstream 02 sensors 2. check and listen for any potential leaks.
Thanks again for any insight and feel free to ask for any further information.
Josh
My name is Josh and have followed IH8MUD since high school when I got a '90 FJ62. Recently got into a 100 series though, so thanks for being here!
I've seen a few threads about threshold error codes with multitudes of suggested fixes, bypasses, and hacks. So I apologize for any duplication, however, most of those threads tend to end in a lack of resolution, or people working around solutions. My goal is ultimately to diagnose the actual cause and fix it properly. My ask is for a greater understanding of the system affected by the error codes and steps, tips, guide, etc. for diagnosing the potential issues and the solutions.
I appreciate any help in advance!
2004 Lexus LX-470 in April.
2 Owners. Driven in Louisiana and NC.
250,000 Miles and came with a stack of maintenance receipts (mostly oil changes).
Purchased in Charlotte, NC and drove to Charleston, SC.
Of course CEL, VSC Trac, and VSC OFF lights came on second day I got it when driving around town. It has since taken me coast to coast with no issues like a champ.
In general when on the highway the lights will go off, and when driving in the city they come back on. Doesn't run rough, but there is a strong smell from the exhaust sometimes.
Maintenance I've done unrelated to trying to fix these codes:
-New radiator and hoses.
-New battery.
-Changed oil & filter.
Trouble Codes:
P0420 (Bank 1) Sensor 2 Below threshold
P0430 (Bank 2) Sensor 2 Below threshold
Therefore, from my understanding:
The down stream sensors on both sides are reading too low of values with main potential causes being a bad catalytic converter, bad 02 sensors, or a leak in the exhaust.
Anyone know the best route to start ruling things out?
Current next steps are to 1. Plug the OBDII reader back in and try to check flow rate of upstream 02 sensors and compare to downstream 02 sensors 2. check and listen for any potential leaks.
Thanks again for any insight and feel free to ask for any further information.
Josh
