Removal Of O2 Sensor
Thread Starter
Heel & Toe
Joined: Feb 2006
Posts: 22
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From: Columbus Ohio
Removal Of O2 Sensor
I have a 1985 auto coupe with 125000 miles. I have no idea when was the last time O2 sensor replaced, or if ever. How difficult is it to remove. Do I need to use a penetrating oil before hand. Are they usually "frozen in"? After replacing it, will I notice any improvement in gas mileage?
Team Owner
Joined: Sep 2001
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
At 125K it might be on the decline but if your mileage is OK then its not bad. They tend to suffer a slow death, but my original one was still in the car until I added headers a couple years ago, and I'm at 157K now.
Smartest thing you can do is get the pipes hot and then try to remove it, doing it cold can be difficult.
Smartest thing you can do is get the pipes hot and then try to remove it, doing it cold can be difficult.
3rd Gear
Joined: Apr 2007
Posts: 3
Likes: 0
Removal of O2 sensor
I just did this on my 94 112k. Save your self some hassel and buy the sensor socket. I got mine from Autozone for $9. Make sure to put anti sieze on the threads of the new one so if you have to do it again sometime they will come right out. Make sure not to get it on the sensor part! Then enjoy. Mine ran alot better after I did this.
Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
I've only replaced mine once in the past 7 yrs. And the recommendation is to warm up the engine first.....BUT, I don't like getting burnt, so I decided to try removing it cold, I didn't use any penetrating oil either...guess what, came right out...nothing ventured...nothing gained, if you're going to replace it try it cold first, but I wouldn't use an excessive amount of force if it resisted.
Instructor
Joined: Oct 2002
Posts: 121
Likes: 0
From: Hanover Ontario
I replaced the sensor on my 87 last spring. The car had 115K km (approx 60k miles) when I did this. After doing this I passed my emissions test (I had failed with the old sensor) and improved my gas mileage.
As for the job itself.....it took me longer to get the front of the car up on ramps than it did to actually replace the sensor.
As for the job itself.....it took me longer to get the front of the car up on ramps than it did to actually replace the sensor.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
You can buy a fancy tool if yours is hard to get to. Mine is easily reached using a box end wrench, 7/8", I believe. Mine was never too tight or difficult to remove. Do NOT use anti seize on a new O2. It already has it. A small dab is a good idea if putting the old sensor back in.
RACE ON!!!
RACE ON!!!
Team Owner
Joined: Oct 2000
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From: Fort Knox, KY
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Be sure and pick up a spare 02 sensor connector pigtail, too. Then tend to get brittle from exhaust heat and old age and often crack in your hands when you go to disconnect the sensor. NAPA carries them.
