Live4brew

My 98LS with 220,000 recently threw a code suggesting an O2 has gone bad.

I just went on a 400 mile round trip (post-CEL) including 300 miles interstate and 100 miles city driving. I averaged 26mpg.

With that kind of mileage, I question whether the O2 Sensor is actually faulty. Anyone else think similarly? FWIW, I think the O2 sensors are all original.

fixmiester

I think the engine emissions controls just go into an "open-loop" status whenever any CEL codes are present. The engine just uses default values for fuel mix, which may still give decent mileage, but not controlled emissions.

timmy0tool

iTrader: (7)

what was the code? you could just have a faulty heater on the O2 but not the sensor itself. the senor will still read properly if that's the case.

PureDrifter

iTrader: (10)

i hate it when people ask for help on a code and instead of giving us the actual code, give us their best diagnosis at the problem....

post the code please

Live4brew

My bad PD..I was at work and couldn't remember the code.

Code is P0135

arnage

Coincidentally, I also just saw the P0135 fault on a 1999 LS400 w/ 110k mi.

I'm hoping that puredrifter can chime in, but my preliminary research shows that it's Toyota /Lexus part number:

89465-30430

It'd be helpful if someone can confirm that's the case, as it seems it was only confirmed for a 2nd gen GS.. i need to order this part, so hoping that someone can confirm soon.. (and perhaps provide some pointers on where to get best pricing for an OEM plug & play sensor..)

Live4brew

While running my OBDII sensor and viewing results via Android... I could see "Closed Loop" and "Open Loop" depending on engine load.

arnage

poking around on the Sewell site, i think this is what we may both need?.. of course, it'd be helpful if someone with more knowledge of the process could confirm.

http://lexus.sewellparts.com/oem-cat...S400-1999.html

8946550150
$163.63

arnage

bump please... anyone able to confirm?

timmy0tool

iTrader: (7)

that is correct you need the front sensor bank 1 which is the driver's side. i too have this CEL and need to get this done.



best place to get this is sewell and use your club lexus discount! you can also get this sensor at your local autoparts store for much less but i always get OEM parts esp when it comes to these items.

timmy0tool

iTrader: (7)

rockauto.com also carries this sensor manufactured by Denso which is the OEM part. they have it at $50.89! i would replace both left and right sensors just in case.

arnage

thanks, timmy -- do we know for certain that the denso part is plug and play? and isn't just a generic sensor made by the same oem that needs to be spliced or modified somehow for an LS400 application?
//////////////
Actually, I just did a cursory search on it and it seems like it should fit and even comes with the proper factory plug.
DENSO Part # 2344169
Denso 234-4169 Oxygen Sensor

lastly, any tips from people who have performed the repair on how to avoid the dreaded post-repair vsc on/off light (which requires the jumper wire trick on the obdii connector?)

timmy0tool

iTrader: (7)

i just ordered my sensor and i'll tell you when it arrives, but as your search already proves it should be a plug and play deal. i purchased the same part number as you mentioned.

as for installation, the hardest part is breaking the old sensor loose from the header. soak the threads with PB blaster, wait a few mins to let soak, then have at it. as for the CEL, you need an OBD-II reader to clear the code.

timmy0tool

iTrader: (7)

replaced this sensor over the long weekend. i received it from ebay, and it is completely plug and play minus the longer wire. this cleared the P0135 code. like i said, spray a bit of PB blaster into the treads, let soak, then break loose. i rented a o2 sensor wrench from autozone, made it much much easier, esp since this particular o2 was next to the steering box. besides smacking my hand against the frame rail, the tool worked great!

come to think of it, i should have replaced the other bank. oh well, the pass side isn't too hard to get to so i'll get to it when it does throw another code. my friend with a 96 w/over 200k already replaced 3 of his 4 sensors. i assume this is a common wear item.

PureDrifter

iTrader: (10)

post cat O2 sensors are easy.

the pre-cat ones are a pain to get to.