O2 Sensors - Arrrrrrgggghhhh!

[66mgb]

I was thinking about changing out the O2 sensors on my beast. Are there any special tools or techniques to doing this? This looks like a knuckle buster!

[Q45tech]

Be sure to precoat the base of the O2 [do all 4/2 as preventative] with a chemical to loosen the seized threads at least 24 hours before you wish to remove.

I do this every 90 days as part of my 1 hour oil change and rubber treatment exercise. That way everything is always ready to remove if necessary.................same with exhaust system from precats back.

[Q451990]

There is a special socket that can be made to work with several extensions... snake them up between the firewall and engine and turn with a ratchet at the top. The crow's foot in the FSM is probably the best option, but I'm not sure where to buy one...

Heath

[maxnix]

The crow's foot in the FSM is probably the best option, but I'm not sure where to buy one...

Heath

Corral a SnapOn, or even a MAC jobber.

[Q451990]

Free loaner tool set from AutoZone. http://www.autozone.com/in_our...t.htm

Heath

[Jeff Williams]

It took Childs Custom Exhaust 1.5 hours to remove the O2 sensors, and that is on a lift, with the exhaust system out of the way. They were a little perterbed, and charged me an extra $40 for the replacement. I said "Better you than me" when I picked up the car.

My fuel mileage is much better with the new O2 sensors. Maybe even 5% to 10% better.

[tkd_q45]

Is 02 sensor replacement any easier w/the plenum pulled? I will need to do plenum hoses on both Qs soon and am thinking of doing valve cover gaskets and spark plugs at the same time.

[Q451990]

No difference... plenum or no plenum.

Heath

[Rex]

Is 02 sensor replacement any easier w/the plenum pulled? I will need to do plenum hoses on both Qs soon and am thinking of doing valve cover gaskets and spark plugs at the same time.

Knock sensors and the accompanying harnesses may be, but o2's aren't .

[3Q Jay]

Tom-I'll disagree a bit here and claim that the DS/O2 would be a straight shot from up above when plenum is removed. i'm kicking myself for not doing this last summer when i had the plenum off. agree that PS/O2 would not be easier. VCG slightly easier on DS when plenum off since you already have the snorkel/TB off and EGR discon'd. same logic for spark plugs.

hey did you score your lowering springs?

[sdkhalsa]

For my 94'!Q I had an easy time changing my passenger side O2 sensor. Used a straight 24" extension with a Proto Brand 7/8" crows foot(appears to be a 10 pt variety). The advantage of using this long extension was that it could be inserted straight down from above whereas the short extensions would tend to come apart in the process. After threading socket and extension to a place directly above the sensor, I reached in from below for final positioning. One note of caution, I would highly recommend against using the standard O2 tool as it tends to wobble and can shear off the top of the ceramic portion of the O2 sensor. The advantage of using the 10pt variety crow's foot vs. the 6pt. is that it gives very precise control for engaging the sensor. Time was about 15 minutes. Meanwhile, as for the driver's side, I recall using something like a 12" extension connected by a u-joint to a 4" extension. This was inserted just a fraction to the right(towards driver side) of the center line along the firewall over to the sensor. To position it required a flashlight at an extremely tortured angle. Getting this visual was the key to the process. I would advise against using more than one u-joint as it is too hard to control the movement of the tool. In order to do this driver's side, required disconnecting the power brake vacuum line and opening up some cable and electrical retainers. If you position everything well, it can be done in about 20 minutes.

[PopPop]

There are several options on this from bottom of the Q with a Stubby 21mm or 22mm open end wrench or from the top side with 02 sensor deep socket with long or multi-extensions! I found that the extensions with a ball-swiveled end work best because of the angle at which the 02 sensor sits on the DS. PS is fairly easy to get to! I never had a problem with these seizing up I guess it's all in the power of the forearm!

[66mgb]

You're right - the driver's side was the easiest. Ended up taking it off in about 30 min. From below, used 2 -12" extensions and a crow's foot to do it. Car was on a lift so I could see what I was doing. Soaked the old sensors in PB Blaster prior to removal.Passenger side was a pita. Ended up having one guy thread the crow's foot down from the top (2 - 12" ext. w/ ujoint) while I guided it from the bottom. 1.5 hrs. on the passenger side.I had to run out to Sears to get a new 3/8" ratchet - free replacement due to years of abuse. God I love Sears for their tool policy.After we had both finished, I wondered if it would've been wise to put a light coat of anti sieze on the threads. Oh well maybe next time.I'll be curious if gas mileage changes much.

[sdkhalsa]

I think that my success on the passenger side was in not using a ujoint. If you insert the extention at the right spot it is a straight shot to the sensor at perfect angle. Minus the ujoint you can put a lot of force on the sensor to break it free. I found that once the sensor turned, it could be unscrewed from below by hand. With the 7/8' 12pt crows foot(3/8' drive), you engage virtually every facet corener of the sensor and there is no slipping or stripping. This Proto Brand was very good because it is somewhat deeper and sturdier than a standard crowsfoot and you can really crank on it. Picture is available on their web site.