mandyfig

Connector removed. Letting the Pb Blaster to soak on the shield bolts. Need to get the shield out to get to the O2 sensor.

mandyfig

The bolt heads snapped on the shield mount. I guess the shield is not going back...now letting the O2 soak on the PB Blaster. Time to drain the oil.

Pennzoil Platinum and OEM Toyota Filter, done!

mandyfig

The O2 sensor came off without a fight. Installed the new one, dabbed a small bead of ant-seize and no shield for the O2 sensor. Disconnected the battery and re-started. Now on to a road trip. Not bad at all. A lot of patience required.

Harold57

So can you tell a difference?

mandyfig

Not really.

I am more annoyed by the lights on the dashboard.

I have replaced a defective component which is key in making sure that the combustion is at its peak efficiency and there is no unburned fuel escaping to the atmosphere.

Bgw70

Great job Mandy!
I guess you are good to go again, no CEL?

mandyfig

No CEL so far...

My old O2 sensor wiring was pinched between the engine and the tranny (?) line. It was wedged in there tight. I did not even check the condition of the wires.

nc356

iTrader: (1)

Mandy,
Thanks for more info!
Questions:
1: Did you do the work through the wheelwell? (How'd you get those pix with plastic wheelwell in place?)
2: Any chance the wiring was broken by the pinching; this could have opened heater circuit and generated the code?
3: Did you use a special socket for the sensor? Source? Size?

Harold57

Nice job Mandyfig. Having that light on would annoy me also.

Bgw70

I can answer question three for you. Every O2 sensor I have seen is the same size socket. Mine is a K-D3259

mandyfig

1. I had to put the front in stands as I normally would do when changing the oil. I did not remove anything but had to remove the tranny ($) line mount which was not a big deal and tie wrapped it away so I can have more space to get into the connector. In fact I forgot to un-tie it and when I was rmounting the undercover, I had something blocking the screw hole and there it was the mount...needless to say, I had to re-install it, 2x 10 mm bolts.

2. I did not think it pinched the wiring that hard that a wire would have been broken. But I had to yank the tranny pipe to let the wire go. I did my ohm check on the old O2 sensor and it failed.

3. Sensor adapter, I used the Advanced Auto one that I have had for years. Works like a charm. I have the compact one.

LS430cb

Just finished doing mine, you don’t have to remove the heat shield to replace the o2 sensor for anyone else who needs to do theirs in the future.

vb9594

Just did this. Extremely doable, but a bit of a pain, nonetheless. A few tips for replacing the O2 sensor:

1. Get the special socket. It's $8. Get it.

2. The connector to the wiring harness is tough to find. It's right below the alternator but there is another connector to the oil pan in front of it so it is tough to see. It's also mounted on a metal tab- I pushed it off with a flathead screwdriver.

When you take out the old wire just cut it. It's the easiest way to do it.

3. When finished, if you follow the above instructions, you'll disconnect the battery, then reconnect it, start the car and see the VSC lights come back on when you put it in drive and then start rolling. You'll curse the universe and cry, but then you'll click this link and follow the instructions in post #7 to reset the VSC calibration...then you'll be all set!

https://www.clublexus.com/forums/sc4...ff-lights.html

jimisbell

Are the upper and lower sensors the same part number? I just ordered one and forgot to specify which. I hope they are the same!

The readout at Auto zone said "4 required" so I assumed they were all the same?

GmanSC

Jim, what year is your SC. Before 07, they are color coded and all different. 07SC and later, they are the same for all four.