Air/fuel Ratio Sensors

[golfnut]

Hi Guys I am a new member and I have a problem with Code 1155 on my RX 300 (2001).I have replaced the sensor but my management lights wont stay out and fault code is still coming up 1155.Any Ideas

[RX300 Lover]

Hi, currently have same problem with P1135 and P1155 codes displaying on a 2001(Y) plate.

check out here and you will find a link to download a technical manual. Pages SF-75 to SF-77 have information on the air-fuel sensors with relavent ohm/resistance measurements. I noticed this manual is for an 03 model so I am not 100% sure if the 2001 sensors will have the same measurments, if anyone could clarify this would be great.

This pdf file shows how to check the ECM for correct voltages to the sensors which would be worth doing if you think your old sensor was fine to rule it out.

Did you check the resistance of your old sensor BTW?

[RX300 Lover]

Ok I've just taken my 2 sensors out which are:

Bank 1, sensor 1: Under and behind the engine block(right bitch to get to)

Bank 2, sensor 1: On the outlet manifold(easy to do)

The resistance measurments(taken cold) were as follows:

Bank 1, sensor 1: 0 ohms

Bank 2, sensor 1: 16 K-ohms/16,000 ohms

As I understand it the resistance must be in the range of 0.8 to 1.4 ohms otherwise computer will display the P1135 and/or P1155 codes so I take it my sensors are toast.

I'm going to remove the glove box and check the voltages from the ECU too.

[RX300 Lover]

Ok, I have replaced both sensors with Denso DOX-0243 sensors(£75 each inc vat) and the fault codes are gone and the car is driving fine.

FYI both new DOX-0243 sensors resistance measured 0.8 ohms so it would seem DOX-0243's are fine in RX300's.

[RX300 Lover]

Update: I drove car for about 10 miles and CEL came on again this time with codes P0174(bank 2) and P0171(bank1) both of these are "Sytem too lean" errors.

[Jezza]

Hi rx300

I too had 1135 and 1155 codes. Fitted two new sensors Dox 0243's from sparkplug co. thanks to this forum. re set fault codes and all ok.

2001 rx300 by the way.

Re System too lean" is your MAF sensor clean? The one in the air intake aperture of the throttle body. This can get mucky and throw the mixture. A careful clean with cotton bud and isopropanol will do the trick.

Also I read on Club lexus if the air filter box isn't seated properly that can throw the mixture and get an engine light.

Worth a check.

[RX300 Lover]

Bit of a long time to update this but just to confirm these sensors were fine and my car is running perfect.

[Boxbrownie]

So what did you do after the code reappeared? Or did the fault code just turn itself off eventually?

[RX300 Lover]

If memory serves me correctly I disconnected the negative on the Battery and cleaned the MAF sensor then all was fine.

I used a proper MAF cleaner the Liqui Moly Mass Air Flow Sensor Cleaner

one but judging from the smell its just isopropyl/rubbing alcohol anyway so you may as well just use that as it'll be cheaper.

Oh by the way does anybody know what the sparkplugs.co.uk product number/code is for the AF sensor at Bank 1 Sensor 2 as it is NOT the same as the other two?

[Jaspersilus]

Hi,

DENSO 234-4215, dont think sparkplugs.co.uk do them, amazon is the place to go!

Cheers Jason

[RX300 Lover]

Thank you Jason.

Just for peoples reference the sensor at Bank 1 Sensor 2(DENSO 234-4215) should read 11 - 16 Ohms resistance (cold/20C).

I'm gonna get my drivers seat out and test the Ohm measurment of my sensor as I've been getting CAT fault codes(P0420) come up and I reckon this sensor is on the way out and causing it.

Will post results as and when.

[Jaspersilus]

Hi,

just for clarity, its amazon.com not .co.uk!

cheers Jason

[Boxbrownie]

Just be very careful with amazon suppliers, the first sensor I bought was sold as a Bosch unit, when it arrived it was marked as Bosch but by its appearance and packaging including the fact it came without the instructions and gasket it was a fake, needless to say I returned it, luckily it was refunded without argument........I then bought another which was the same part number from another supplier and it was obviously the genuine article............sometimes cheaper is not better!

[RX300 Lover]

Does anybody know the UK Denso part number or OE number for DENSO 234-4215 sensor as I contacted Sparkplugs.co.uk and got this response:

Unfortunately we are unable to reference Denso part numbers in this format,
these are usually USA market numbers and cross reference to a European
number is not readily available. If you have the vehicle manufacturer's OE
number (read from the installed sensor or ask a main dealer) we may be able
to help.

[RX300 Lover]

OK after some research I have found that UK Denso part number (for US DENSO 234-4215) is DOX-0227 which corresponds to:

Toyota OEM # 8946519595 (which is also the same as) Lexus OEM # 8946549075

Hope this helps someone save some money.

P.S I am waiting for a sensor to be delivered will update when installed.

[ColinBarber]

OK after some research I have found that UK Denso part number (for US DENSO 234-4215) is DOX-0227 which corresponds to: Toyota OEM # 8946519595 (which is also the same as) Lexus OEM # 8946549075 Hope this helps someone save some money. P.S I am waiting for a sensor to be delivered will update when installed.

you may find it is actually the CAT rather than the sensor at fault. Do you know what your emission readings where at your last MOT? It may have been near the limit.

[RX300 Lover]

Possibly yes. But the sensors 12 yr old now so I'm betting it's the sensor. I'll test the old sensor when I get the front seat out if it's ok then it will confirm CAT in which case I'll take them off and clean them out.

[ashwath]

I have Lexus 2005 Rx400h MHU38R-AWXGKW uk model. I been
given error code P2197 which says Oxygen (A/F) sensor signal struck lean (Bank
2 sensor 1) by my regular mechanic and a suggested part number by Lexus dealer
as 89467-48060.

I understand that there are 4 sensors.

Firstly where does this sensor fit and is the part number
correct for the error code description. Please advice.

Many thanks in advance