I just bought the car, so do not know if there are mpg issues or anything like that. It has 203K on it, and it doesn't look like the previous owner was too much into preventive maintenance like replacing parts without codes.
Here's what I have so far:
The Codes:
P0420: Rear bank catalyst efficiency issue. Lexus tech in another thread says 99% of time, this code is a short in the O2 sensor heating circuit. New sensors are $100 for front and $30 for rear, so $260 for whole set.
p0443: Evaporative Emission Control System Purge Control Valve Circuit Malfunction (new valve is $50 to $100). Could also pull valve and test to see if valve and hoses hold vacuum.
p0497: EVAP System Low Purge Flow. I read somewhere that this could be due to dirt in hose from canister
I'm waiting for a friend who is a shade tree mechanic to take a look at it and narrow down the possibilities, but I wanted to know what you guys thought. From my experience, cars tend to develop similar issues, so other's experience is helpful.
My gut feeling was to replace all O2 sensors, since they probably need it anyway. On the other hand, I hooked up my odb2 dongle and looked for o2 sensors with torque app. The downstream O2 sensors moved between 0.3 and 0.6 or so over a period of 10 seconds or so. They were not real steady, but did not bounce around quickly like they might with functioning O2 sensors and a dead cat. I could not get anything useful out of the upstream O2 sensors (air fuel mixture sensors?). I'm not sure how to interpret those.
Might the Evap system issues be linked or do people think that these are different issues?
Here's what I have so far:
The Codes:
P0420: Rear bank catalyst efficiency issue. Lexus tech in another thread says 99% of time, this code is a short in the O2 sensor heating circuit. New sensors are $100 for front and $30 for rear, so $260 for whole set.
p0443: Evaporative Emission Control System Purge Control Valve Circuit Malfunction (new valve is $50 to $100). Could also pull valve and test to see if valve and hoses hold vacuum.
p0497: EVAP System Low Purge Flow. I read somewhere that this could be due to dirt in hose from canister
I'm waiting for a friend who is a shade tree mechanic to take a look at it and narrow down the possibilities, but I wanted to know what you guys thought. From my experience, cars tend to develop similar issues, so other's experience is helpful.
My gut feeling was to replace all O2 sensors, since they probably need it anyway. On the other hand, I hooked up my odb2 dongle and looked for o2 sensors with torque app. The downstream O2 sensors moved between 0.3 and 0.6 or so over a period of 10 seconds or so. They were not real steady, but did not bounce around quickly like they might with functioning O2 sensors and a dead cat. I could not get anything useful out of the upstream O2 sensors (air fuel mixture sensors?). I'm not sure how to interpret those.
Might the Evap system issues be linked or do people think that these are different issues?