mgamez

I just took my 2001 rx 300 for emission test in arizona and it failed for the following codes:
P1135 air/fuel ratio sensor heater circuit malfunction (bank 1 sensor 1)
p1155 air/fuel ratio sensor heater circuit malfunction (bank 1 sensor 1)
my check engine and vsc light were on when i took it in, i had to replace the battery two weeks ago and that is when the lights came on. Need help to fix before going to a shop and spending a ton of money. Thanks

Rainbird

This should have been posted in the first generation forum. I did a search on the first generation forum and found several postings that may help:

https://www.clublexus.com/forums/rx-...and-p1150.html

https://www.clublexus.com/forums/rx-...and-p1130.html

https://www.clublexus.com/forums/rx-...el-lights.html

Here is instructions for DIY to replace the sensors:

https://www.clublexus.com/forums/rx-...el-sensor.html

Rainbird

Here is instructions for a DIY to replace these sensors:

https://www.clublexus.com/forums/rx-...el-sensor.html

salimshah

First, with CEL on, you would most likely (99.99%) would fail emission test. The testing place read the computer, which has already triggered a fail. The discussion about if it is real or not is besides the point [sensor failure or real failure].

Before opting to a fix, I recommend that you note the fail code and then reset the error code. If you get the CEL back on, immediately get it read (to prevent chain reaction errors).

With high milage (100k miles +) usually it is the sensor that has gone bad, but keep in mind the CEL is telling that there is something wrong in the system [sensor, wiring, actual problem].


One more thing, the testing place will send you back if you go to them right after resetting the computer. Enough information is gathered after some miles and number of starts [typically you get there in about 4 days ... sorry I dont have the exact information].

Salim

code58

#1, those are 2 different sensors. P1155 refers to the heater on Bank 2 sensor 1. I don't know where you got the I.D. for DTC P1155 but that ERRONEOUS I.D. has been floating around for years and I suspicion came directly from T/L in error.
#2, COMMON sense says that if it happened right after you changed the battery that you disturbed something in the process of changing the battery that caused that DTC to come on. Go back and look things over again and see what might have been disturbed. I think I can say, without embarrassing myself that the chances of BOTH of those sensors could have the heater go out at the same time as a result of changing the battery are about 3,000,000,000 to 1. Get the picture? Most likely the DTC triggered those codes to get your attention, but had NOTHING to do with those sensors being bad. That is not terribly uncommon.

GS4_Fiend

iTrader: (22)

You should verify that the A/F relay and fuse are good before replacing those sensors.