britrod

Hi, I own a 2001 RX300, just recently we had very heavy rain (12") the street got flooded and my wife tried to get back to our house. The vehicle didnt stall but she was pushing a lot of water. The next day the VSC,Trac and engine light came on...Autozone plugged in the code reader and its a P1135 a/f ratio sensor heater circuit malfunction,b1s1. Any info on what I can do to rectify this would be appreciated.

Thanks.

Rod.

salimshah

Dry out, or let the things dry out and then check.

All electronics including sensors do not like being wet.

Salim

Lexmex

That's an air/fuel sensor behind the engine block. I take it that AutoZone cleared out the code and it still came back?

britrod

Thanks for the welcome. Autozone didn't clear the codes, they just told me what they were. I found the sensor on the rear of the engine located in the exhaust manifold, I noticed there was one at the front of the engine (manifold) and one to the rear, I believe its the one to the rear. They both look dry and clean. I guess i should ask Autozone to try and clear the codes first before going any further.

Thanks again for the info.

Rod.

britrod

Thanks guys for your suggestions-After testing the air/fuel ratio sensor located in the rear manifold near the firewall, it read open circuit instead of the .8-1.2 ohms as you had mentioned. I picked one up from the local Lexus parts ($160+) ouch, expensive little devils. I also picked up a OBD 11 code reader from Harbor Freight for $38 - changed the sensor which unscrewed very easily (was expecting it to be really difficult with all that heat/rust) replaced with the new one, cleared the code P1135. All is working fantastic.
Still dont understand why the Trac control,VSC and engine light came on for something directly associated with the fuel/air mix and emmisions. I love Club Lexus and all the guys who take the time to offer the experts knowledge.

Thanks again guys. Rod.M.

bob2200

I think all three always come on as a "check engine" indication. I suspect it was done because you are less likely to not notice three lamps coming on.

lexus114

I second that bob,it`s the only reason that makes any sense.