How to Disconnect Upstream O2 Sensor Plug (1 Viewer)

[TheBestCow]

I’ve found my upstream o2 sensors. I am working on bank 1 driver’s side.

From what I’ve read, the disconnect is on the back side (so not any of the sides I am pointing the colored arrows at).

I have tried squeezing the back side and opposite front (so above the red arrow) with one hand and pulling with the other to no avail.

I’m trying not to be an idiot, so slowing down and asking here. Figuring using a vise grip to squeeze both sides is likely to break the “engine side” connector which would necessitate other repairs. Have read some people suggesting using a flathead to push on red arrow side, but again don’t want to shatter the beige holder.

It’s got some crud up in there but thinking spraying PB up and around it will not be helping me because the outer beige part will be more slick.

Any tips?

 

[NorCalFJ100]

I’ve found my upstream o2 sensors. I am working on bank 1 driver’s side.

From what I’ve read, the disconnect is on the back side (so not any of the sides I am pointing the colored arrows at).

I have tried squeezing the back side and opposite front (so above the red arrow) with one hand and pulling with the other to no avail.

I’m trying not to be an idiot, so slowing down and asking here. Figuring using a vise grip to squeeze both sides is likely to break the “engine side” connector which would necessitate other repairs. Have read some people suggesting using a flathead to push on red arrow side, but again don’t want to shatter the beige holder.

It’s got some crud up in there but thinking spraying PB up and around it will not be helping me because the outer beige part will be more slick.

Any tips?

View attachment 2578400

Can you spray some compressed air in there to clean out the dirt? Harbor freight sells these hose clamp pliers. Ive used those wrapped in tape so they're not as sharp at the ends to get off stubborn plugs before...but be careful, too much force and you'll break the plug.

 

[JunkCrzr89]

Press at the purple arrow to unlock. Wiggle while pulling.

 

[TheBestCow]

Can you spray some compressed air in there to clean out the dirt? Harbor freight sells these hose clamp pliers. Ive used those wrapped in tape so they're not as sharp at the ends to get off stubborn plugs before...but be careful, too much force and you'll break the plug.

Good idea on the compressed air... I will give that a shot while waiting on any other suggestions.

And yea, I don’t have hose clamp pliers but afraid of breaking the plug. I figure I can keep pulling on the dark gray part (of the soon to be replaced o2 sensor) without fear, but trying to do everything I can to protect the beige...

 

[TheBestCow]

Press at the purple arrow to unlock. Wiggle while pulling.

View attachment 2578409

Thank you! Pressing didn’t work perfectly but once I changed my angle I could see that’s where the clip is. Worked a tiny flathead in just enough to pry the clip off the dark gray part (stuck with crud) and then slipped the screwdriver out and continued to squeeze at the top of that clip (engine side) and pull with the other hand.

Surprisingly the passenger side was easier. Clip was workable with my hand - could hear it click - and got it loose.

Now to let the PB soak in and wait on Amazon delivery.

Will report back later. Thanks for the help.

 

[bigredmachine]

small screwdriver is a good option, sometimes pushing the connectors together will take enough pressure off the lock tab to be able to unlock and pull the connectors apart

 

[bigredmachine]

you might want to start the truck up to heat the exhaust and respray with pb to try to help it work in

 

[Live to Ski]

Related: Anyone have a picture of the cable mounting bracket?

Reason: according to dealer, that bracket was missing on mine, led to a short which mimics the MAF codes (and non-start condition).

Thanks in advance!

 

[TheBestCow]

Also, I know I need to disconnect battery for 30 minutes, will do that before I start pulling the sensors. Once everything is reconnected, do I reconnect battery, start LC, idle for 15 minutes? Or do I reconnect battery, start LC, reset CEL with Techstream, then let idle for 15?

 

[bigredmachine]

Also, I know I need to disconnect battery for 30 minutes

why would you disconnect the battery to change the sensor, never done that in 13 years and never had an issue. change the senor, clear the cel and drive the truck

 

[TheBestCow]

why would you disconnect the battery to change the sensor, never done that in 13 years and never had an issue. change the senor, clear the cel and drive the truck

Hmmmm multiple threads said ECU needed that to be reset and then to re-learn with new sensors. Or so I thought!

 

[JunkCrzr89]

Hmmmm multiple threads said ECU needed that to be reset and then to re-learn with new sensors. Or so I thought!

As @bigredmachine said, no need to disconnect battery. Just swap the sensor and clear the codes via Techstream or other OBDII reader. The ECU will then complete the readiness monitors over the subsequent drive cycles (i.e., “re-learn” with new sensor).

 

[bigredmachine]

Hmmmm multiple threads said ECU needed that to be reset and then to re-learn with new sensors. Or so I thought!

nope just drive it, when you replace the sensor make sure that it is a denso or ntk. ive had to replace brand new cheep aftermarket sensors because the code came back after replacing it.

 

[TheBestCow]

Sensors installed, son learned something, cleared the codes... on we go to the next thing! Thank you for the help!

Will report back if there is a dramatic increase in fuel economy but not holding my breath.

 

[TheBestCow]

Actually, quick question. TechStream is showing O2FT B1 S2 at 99.15% vs -2.38% for B1 S1 and -0.04% for B2S1. Not seeing a reading for B2S2 either.

Do any of these values look incorrect or indicative of some other problem? My original code was for B1 S1 needing replacement.

Photos of the old sensors: