hi Lexmex and guys,
inspecting a/f sensor
I bought my rx300 at the end of 2013 with a big help and tips from lexmex
changed all thing (spark plugs maf,etc) trying follow reducing MPG
never reached in good place like a lot of you.
then i decided inspect a/f. i got a lot of information from CL mainly the aspect of the probe of o2 and a/f. was hard to unplug. Then I cutted the tool (as i show in the photo, to me in my age i'm more important then the tool) worked very well. the connector wires pass thru the tool.
you all will not believe. they are differents, and one B1S1 is open no resistence.
the other (lot of holes (maybe is a O2) shows 14.0 Ohms)
see the photos.
then, was that, i have to buy two new parts.
maybe now i will make a good MPG

 

What is Denso's part number for bank 1 sensor 2?

 

http://densoautoparts.com/find-my-pa...icle-selection

 

Got it. Thank you.

What is the best way to clear the Check Engine warning light after replacing an A/F sensor?

My understanding is that (1) disconnect battery would wipe out all setup (memory) and back to the initial default; (2) unplug the ECU fuse would loose accumulated driving info and learned A/F mix.

Is there a simpler way just to clear the Check Engine warning light?

 

If you have a decent code reader, you can clear the CEL with just a few taps, if not
disconnecting the battery is the simplest way. It would also accomplish your #2 point.

Drive it smooth and normal after replacing the A/F sensor to slowly build up the short/long term fuel trims in the ecu.

 

Never heard anyone give this advice before. Have changed out quite a few AF sensors, never did anything special to slowly build-up fuel trims and never had an issue. STFT's correct immediately and LTFT's follow quickly.

 

I've done extensive logging on many other NA cars and turbo cars on the dyno, when the ecu is reset and short term fuel trims have yet to be defined, driving hard right away can throw the trims off due to abruptness. Its garbage in/ garbage out in terms of learned data and works its way into the long term fuel trims and mpg will be affected. The choppiness will add/subtract fuel unnecessarily.
Small intake leaks between the airbox and throttle body will exacerbate the bad learned trims if they haven't been discovered.

There is a +/- room for adjustment with the fueling table, based on the detected air flow from the maf but you want that transition smooth as possible.
This is why i advise to drive smooth and normal, the ecu is in a "learning mode" state.

 

There is a certain level of sophistication in the auto learning. 99 RX was at the early stages as this auto-calibration grew in the auto-business. I dont mean to say there was very little, carburetor was out but throttle by wire is not in 99 RX.

Salim

 

My CEL, VSC and VSC OFF lights are on, RX300 2002. Autozone said it was the MAF. I replaced the MAF but the lights are still on and will not pass inspection. Now, Autozone said code P1135 code-replace A/F sensor...could it be something else or should I replace 2 A/F sensors? help

 

welcome. Stick with Denso or OEM sensors . read this thread https://www.clublexus.com/forums/rx-...ode-p1135.html

 

Thanks...Autozone sold me an OEM part (so they said) and it did not work. Purchasing Denso will fix the problem?

 

By the way, after the new MAF sensor was installed. The lights came back on...then, Autozone did second check...new code P1135? I'm so totally confused?

 

P1135 is not a maf code. Most posts that show a/f sensor related problems and Autozone involved, they push Bosch sensors. Autozone does not carry OEM Toyota/Lexus parts. Just say no to German parts on Japanese cars.

Read the whole thread

 

Gotcha...they originally said it was the MAF sensor. Replaced it, lights still on. Then, code P1135 popped up. I'm going to order the Denso MAF but if it does not work, what else might it be?

 

Never, ever depend on Autozone to diagnose your code. Get your own reader, clear all the codes and drive until the CEL comes on. Read the code and post it here for advice. How many bucks did you just waste on that MAF sensor?