Ordered new O2 sensors, beyond needing a ton of penetrating oil any other known problems changing them out. Doing all 4.

 

My plugs for the front sensors were really stubborn. Used a little bit of WD40 to get the plastics loose and a long needle nose plier to reach up to depress the switch to release helped a ton and made quick work of the plugs. Took me about 25 mins to do all of mine. I didn't need penetrating oil on the sensors but my truck has been a lifelong CA truck and prev owner didn't take it off the pavement.

 

Actually all 4 of mine were easy to remove and replace.
Remember to route the wires so they are out of the way and don’t rub on the drive shaft.

 

I’ve never had trouble removing them either, but a previous vehicle I had said to start the engine for a few minutes to heat it up. I’ve never needed to do that but if you find a seized it would be worth a try.

 

Remember to use a sensor-safe anti-seize on the new O2s before you install them.

 

Thanks all thinking happy happy thoughts, will update thread with anything I found useful while doing it.

 

It's been 3½ years since I last had to change an O2 sensor, but here are a few things I remember from that instance and far too many before that. I'm confident I could now change the front, upstream sensors while blindfolded! I have never changed the downstream, post-cat sensors (more on that later).

First, if you are doing the job for the first time the most annoying part of the job may be releasing the wiring connectors. They're not quite so annoying as the CKPS connector, but the ones for the front O2 sensors aren't convenient to reach. I recommend sliding the connector off the little bracket to which it is mounted and then pulling it out from behind the head.

Once it's freed from its mount, disconnecting it is easy. Then, don't return it to its mount, just use a zip tie or a twist tie to secure it so that it doesn't end up resting on the exhaust manifold. That happened on my truck, but luckily I caught it before any real damage was done.

As for the sensors themselves, I've never had any problem removing them. Yes, they're in there snug, but the anti-seize compound must have done its job. (New sensors are shipped with anti-seize already applied to the threads.) Just use your standard 3/8" drive ratchet and several extensions so that you can turn the ratchet from a comfortable position a couple feet up from the sensor. I have and I've used both styles of O2 sensor socket, and I now prefer the offset style linked below since there's no issue with the wires getting in the way. That said, I evolved to prefer just using an open-end wrench from below to remove the Bank 1, Position 1 sensor (driver side, LHD).

What is prompting you to replace the O2s, especially the downstream, post-cat sensors? Is the SES on, and you found O2 sensor codes? As for the downstream sensors, they have nothing to do with how the truck runs. Their only purpose is to monitor effectiveness of the cats.

https://www.harborfreight.com/3-8-ei...nch-97177.html

 

I learned that the nice offset O2 socket I bought can damage the sensor if it is not held almost perfectly straight. Ouch

 

@mln01 Specific codes for the the rear O2 on one side, both warning and failure, they re-occur every other day and I hate the CEL light. I have had codes for the others as well but very random. In may case it is just being proactive the PO was a bit slap dash in his work.

 

I'm SOOOOOO pissed...first off, I'm not a mechanic by anyone's standards. But, the fact that I just spent $750 on a new O2 sensor today makes me wish that I'd at least given it a shot, lol