smerre01

Hey gang,

Need some help if possible, the CEL came on the other day took it to Lexus for a diagnosis verbatim this is what my service receipt states:

Cust states check light is on
P071 - Air Flow Meter Bank 1. Too Lean
P1135 - Air/Fuel Ratio Sensor. Bank 1 Sensor 1
Will need A/F Sensor and AIR FLOW METER.
Parts + Labor: 635.65 + Tax

I believe the Bank 1 Sensor 1 is the "upstream" sensor on back side of the engine and not on the exhaust system, can someone verify the location of this sensor? Also when I go to advance auto website they only list the sensors as upstream and downstream, I can't tell which upstream sensor would be the right one, are they all the same???

Also what is the Air Flow Meter? I have looked in my haynes manual and so forth cannot figure out what this is, not in the index, and I have no clue. Anyone heard of this?

Thanks!

smerre01

Okay I think the Airflow Meter is really the Mass Air Flow Sensor over near the air filter box, still not sure on what damn O2 Sensor I am looking for. Advance Auto is ranging from like 80 bucks to 326.00......

thomas1

You might just try clean the MAF sensor, and check your gas cap....Unplug the battery for 10 minutes and then see if the code comes back...

Here is how to clean maf sensor:

http://www.lexusownersclub.co.uk/kno...v2&id=152&c=11

blueridge

Autozone sells a special MAF cleaner in an aerosol can. Just spray directly into the MAF, shake gently and it will dry in two min. Works very well for me and I will do this every 6 months.

smerre01

I will have to give the spray a try...didn't know it existed, just got back from Advance Auto and I got the O.E. Bosch Oxygen Sensor part # 15217. In case anyone else is ever curious about O2 sensor positions let me attempt to break it down:

Bank 2 is the side of the engine facing the front of the car (open the hood the closest side of the engine is Bank 2)

Bank 2 sensor 1 is upstream or before the catalyst should be easily visible on the manifold around mid cooling fan area on the manifold. This is a A/F Sensor.

Bank 2 Sensor 2 is a Heated Oxygen Sensor located in the exhaust pipe I believe this is pre catalyst as well. Still on the same side of the engine (Bank 2)

Bank 1 is obviously opposite side of the engine from Bank 2 and is the side of the engine closest to the firewall. From a top down look I wasn't able to see the sensor, so you will have to crawl under the car.

Bank 1 sensor 1 is another A/F Sensor located on the manifold on the rear of the engine.

Bank 1 Sensor 2 is another Heated Oxygen Sensor located further down the exhaust coming from the manifold on the rear of the car.

Crappy description I know, but hope that helps someone else out.

I did buy a MAF sensor or "Air Flow Meter" it was 80 bucks for the new one, and is located right along the top of the airflow intake from the air cleaner box and is easily changed.

Thanks for the replies guys, I appreciate it once again!

smerre01

Nice instructions on cleaning the MAF Sensor, may try that and take this new one back.....

Don't know of any instructions like that for replacing the passenger front door lock actuator/motor do you? Damn power lock quit working on the passenger front this week, been a rough week, I see it move maybe 1/8th of an inch like it wants to open, but just doesn't. I can do it manually all day long with no problem. Figured the actuator has went kaput.

blueridge

You may need to take back the O2 sensor too, I got my money on cleaning the MAF will wipe out the codes you have. #2 would be the gas fill cap gasket, while I was at Lexus in May getting some work done (before I saw this site) there was three cars there for a CEL and it was the cap gasket.

smerre01

HA HA Gas cap gasket, that is hilarious!

code58

Smerre- I hope you mean that as a joke because that is exactly what sets the light sometimes- that and not having the cap properly tightened.
And good luck with the Bosch A/F ration sensor. Some people have tried them with good luck, others with no luck. I personally wouldn't use anything but original equipment Denso. They do work!, and some have chased their tail trying to figure why replacing the sensor didn't cure the problem, only to find out that Toyota and Lexus sometimes don't like Bosch and other aftermarket sensors.

code58

Smerre- The lock actuator replacement has been talked to death on this forum and the other Lexus forum (including many with pictures) Search properly and you'll come up with plenty on the subject. Almost for sure the little tinkertoy hobby motor has worn out. The little ants that power that thing get tired after a while. LOL

smerre01

Yeah it was a joke Code58...... I just found it to be funny at the time, well I still do, made me laugh, yet another gasket to contend with, lol

R.G.

My experience - 2000 RX300:

About 2 years ago CEL came on. I went to Auto Zone and got codes 1130, 1135 A/F Sensor. Replaced it myself with a Bosch bought online. About 50 miles CEL came back on. I was just too busy to chase my tail on this and decided to bring it to a highly recommended Toyota mechanic. After 2 years of having a "professional" change different sensors every 50 miles or so, poor gas mileage, overdrive (safe mode) problems and (I believe) my CEL burning out, I decided to try once again. Thanks to the great information on this site I found that some of the Bosch sensors are not quite adequate for our cars. I went to a local Toyota dealer and bought a new A/F Sensor part # 89467-48011 - I brought a volt/ohmmeter with me and checked it at the parts desk, about 0.8 Ohms. 80 miles and no codes. I will keep my fingers crossed...

I would check the A/F Sensor. Check resistance between the heater element leads (black wires). It should be between 0.8 and 1.4 Ohms. If it is not, replace it. It seems a failure on this part will eventually cause other problems and other codes to pop up making it harder to diagnose the problem.

Good luck!

Rich