P1130 And P1150 Dtcs...

[Kauz]

The check engine light came on and stayed on for a day or so (short driving distances) on our RX300 (90K+). Then, after a couple of days, the light went off and has stayed off for a couple of weeks. I read the error codes and found out that there were two of them:

P1130 Air/Fuel sensor range/performance malfunction (Bank1, Sensor 1)

P1150 Air/Fuel sensor range/performance malfunction (Bank2, Sensor 1)

I also read the freeze frame data and it showed that the P1150 fault was detected at around 2000 RPM, 25 MPH, coolant teperature 138 degrees F, IAT of 50 degrees F. I have not checked the O2 sensor signals yet.

I'm not really sure at this point what may have caused the error codes. But, since the codes indicate that both sensors malfunctioned at the same time and since every thing seems to be fine now, I am thinking that the problem may have been due to some other fuel related issues such as dirty injectors. Not really sure though. Has anyone run into a similar situation? Any thoughts?

Thanks,

Kauz

[Brian in AZ]

If it were me I would clear the codes and see what happens. If it triggers the light again hopefully the new code(s) will be more definitive. It seems very odd that both of the sensors would go at the same time. It may have been something else that caused this code to trigger. These codes are not alway black and white. They help guide you on where to start looking for a problem but sometimes further testing is needed. I have read that if you are lucky a common issue that triggers weird codes is if the black hose comes off the back of your air filter box. It may not be your issue as the light went back off but worth a check.

[92Lex]

Check the sensor heating elements.

[Kauz]

Check the sensor heating elements.

I think that there is a different code for the heating element malfunction. The car seems to be fine for now but I'm thinking that it will eventually show up again. I plan to purchase an OBDII scanner capable of showing live sensor data. Maybe I'll be able to do better tests. (Actually I think it's just an excuse to buy another toy. :P )