Oxygen sensor replacement 2003 AC

Hi all, need some guidance. Each sensor has a different part# so I’m guessing each has its own specific location? If so where should I look to find correct placement?…



anything else I should do? Thinking maybe anti seize would be a good idea?

thanks!

 

There is an 2 upstream and 2 downstream sensors. There shouldn't be 4 different part numbers only two as the upstream and downstream sensors are the same for each side. Maybe open and show what the sensors themselves look like.

 

I have 4 different part #’s. I found the 1st sensor location by looking up seller’s info…

89465-09380 is the rear driver side.

 

I just replaced all 4 of mine today. I put anti seize on where necessary. Unplugging the connectors on the front sensors took a lot of trial and error. It was a pain at times. The upstream drivers side is especially tight. I had to do some crazy arm moves to reach it. I was close to removing my aftermarket skid plate for more access but finally got the plug loose.


Hopefully your downstream sensors came with new gaskets. The Denso replacements I ordered off Rock Auto did.

 

Thanks, I’ll use anti seize as well. the rear driver side came with gasket. Got OEM.

 

The rears are indeed different due to the difference in lengths. The way they are mounted and clipped into place causes the difference in length. The rear passenger is 89465-09320 and is the shorter of the 2 IIRC !

from @FirstGenVol recent O2 work showing approx 2 in. difference in lengths....





As for the other 2 that are for the front, 0C140/50, I don't recall there being 2 different ones but they very well could have been. The similarity they did have was they were a bitch to deal with compared to the rear.

link @ McGeorge Toyota to confirm parts....

2001-2004 Toyota Oxygen Sensor 89465-0C140 | Toyota Parts (mcgeorgetoyota.com)

 

@Voss is it too late to send those back and save money by ordering from Rock Auto? Denso is the OEM manufacturer of the sensors.

 

(89465-09380 Rear left)(89465-09320 Rear Right) (89465-0C150 Front Right) (89465-0C140 Front Left) I think you can put both upstreams left or right upstream, same for downstream left or right downstream, just don’t put a downstream upstream. I recommend using copper anti seize and ad an 02 sensor socket will help a lot for the upstream sensors.

 

Got them at McGeorge which saved me a good bit. I finally have some time to myself and as much as I like saving, having time and being in the mood is priceless

 

Thanks. I now see I can find exact location on seller sites. They say each has its own location and match exactly what you said.

 

The sensors for the front dont have gaskets. Are gaskets needed for only the rear?

Any difference in drive/MPG with the new sensors on yours?

 

That's correct. No gasket for the front, only for the rear. I don't have any MPG data yet since I just installed them today.

 

Thanks bud. Butt Dyno feel any improvements?

 

The fronts have a crush gasket, similar to a spark plug.

 

Not yet. Need more drive time.

That's true. I forgot to mention that. And the front ones come with little packets of anti-seize.

I bought the tool that PHM recommended and it worked great.

ARES 70039-3/8-Inch Drive by 7/8-Inch (22mm) Offset Oxygen Sensor Socket - Wire Gate Accesses Sensor from Side, Preventing Damage to Wires

$13 ARES 70039-3/8" Drive by 7/8" (22mm) Offset Oxygen Sensor Socket - Wire Gate Accesses Sensor from Side, Preventing Damage to Wires

https://www.amazon.com/dp/B01C4OB3XC?_encoding=UTF8

 

And my check engine light is on now

 

That sux. Do you have a scanner that can record the 02 voltages with time? Might be helpful to see how its failing.

 

Damn engine just shut off while driving

and won’t start

 

Yes have one in the car. Checking now

 

Bank 2 sensor 1 “repair immediately if driveability issues present”

great

 

This happened after you installed the new sensors? Or you haven't even had a chance yet?

 

Sounds like you got a bad 02 sensor if it shut off the truck. A/F ratio must be way off.

 

Changed them out last night. First time driving with them. Engine was running smooth up till it shut off

 

Hopefully McGeorge replaces it. These have been sitting in my garage for about a month now.

 

That is strange, a bad 02 sensor shouldn’t shut down your truck completely or at-least is not very common on the first gens. Pull out sensor and test the sensor using a multimeter, did you disconnect your battery? Maybe it wasn’t connected back properly? Will the truck start?

 

Maybe it's something simple? Like the sensor connector came loose?

 

I didn’t disconnect the battery when I installed them, was I supposed to?

 

Possibly. Luckily I wasn’t far from home, I’ll go check it out after the game.

Now that I think of it, I’m actually very lucky cause I would’ve been in the freeway if I had decided to go to the big Super Bowl party.

 

Yeah i didn't think it should make the truck shut off either. My check engine light came on but the truck ran fine. Maybe crawl under there and see if something is disconnected. Will the truck still not start?

 

Truck won’t start. Tried a few times and once I saw the scanner say change or you can cause damage, I just let it be.