Y33 O2 sensor replacement write up

[bullittandy]

Just finished the O2 sensors (all 4) on my 97 Q45. Here's a heads up for others attemtping the job. WD-40/JB Blaster MUST be used! Don't try to do anything until the sensor nuts have soaked for at least 30 minutes but the longer the better (I soaked them the night before).

The rears are easy-no caveats. However, I got a little nervous about the fronts when I had to use my mini sledge hammer in order to break the rears free.

The front passenger has been discussed in previous posts-same applies here. Using a O2 socket (crows foot style-rented from Autozone) from the bottom of the car slip it over the sensor. Then from the top of the car in the engine bay drop a long extension into the sensor socket. I used a flex joint to get a better angle.

The front driver was the fun one! I had trouble reaching it from any angle-top,bottom-anywhere. So I removed the master cylinder and brake booster. Do not remove the brake lines from the M/C just unbolt it from the booster and move out of the way. The length of the brake lines aloows it to be moved easily. The brake booster was a little more difficult. It is held on by 4 bolts inside the car-2 of which are easily seen, 1 is somewhat tricky and the 4th nut (upper right from driver's seat) was very difficult. Find access any way you can. Putting this nut back on required me to-are you ready? tape the nut to the end of my finger! With this I was able to get it on the brake booster stud the second try. Overall this was harder than replacing the Knock sensors. I better notice the gas milage increase for all the pain and frustration!!

[paranoidjack]

nice andy thanks! I have to do this soon, from the sound of it I'll just pay someone to do it, I don't feel like wasting 8 precious hours on it!

[bullittandy]

nice andy thanks! I have to do this soon, from the sound of it I'll just pay someone to do it, I don't feel like wasting 8 precious hours on it!

If you get a labor quote for $300 or less than I'd say let them do it. It wasn't worth for me. Of course, the next time I could have it done in three hours! 1st time=X amount of time2nd time=50% of X amount of time3rd time=25% of X amount of time

I use to have a 72 Chevy Step van with a straight six. The first time I pulled the intake and exhaust manifolds it took me 3 hours-the last time it took me 20 minutes!!

[paranoidjack]

took a look at mine today. Replacing rear driver for now....andy you say this was easy?! I have one of those maybe 2.5" sockets with the vertical gap in it for the wire to fit through...not a chance.

I'll have to get the crow's foot o2 that you speak of, cause this ain't gonna work! After 30 secs it was obvious.

[FarFetched]

with a special adapter and impact gun, those things come off like a hats in the wind! Of course pre-soak in PB blaster a must!Cheers!

[bullittandy]

took a look at mine today. Replacing rear driver for now....andy you say this was easy?! I have one of those maybe 2.5" sockets with the vertical gap in it for the wire to fit through...not a chance.

I'll have to get the crow's foot o2 that you speak of, cause this ain't gonna work! After 30 secs it was obvious.

You don't have to get it off in one piece. One of mine ended up "breaking" and so I tore off the metal body and the ceramic inside. This allowed a regular socket to fit over the nut. Of course, you better get it off then because the sensor is toast!Disclaimer-I know, I know, with the right tools it should come off with having to destroy it.

[paranoidjack]

again, unless you want to gift your socket to the car, it's somewhat pointless to have to break off the old one, because to put the new one on you don't have that luxury.

[BadQ45t]

Why did you have to replace them? Was the car nor running right? What mileage?

[bullittandy]

Why did you have to replace them? Was the car nor running right? What mileage?

I didn't have to but the car had 212,000 miles and I didn't think that they had been replaced. I did not notice a mileage drop with the old nor a mileage increase with the new ones. I've heard that they are a wear/maintainence item and that their efficiency degrades with time but I'm thinking that they degrade in the same way that modern spark plugs do-very slowly. My idea's about tune up's come from working on older carbed cars where there is an appreciable difference after replacing parts so the Q45 is a bit of a dissappointment in that sense.

[bullittandy]

again, unless you want to gift your socket to the car, it's somewhat pointless to have to break off the old one, because to put the new one on you don't have that luxury.

Getting the old ones off is the hard part, 10 years, rust, 200,000 miles and exhaust heat all combine to make it difficult. However, they are only difficult because of access-the rears were no problem. Similarly, threading new sensors in and torquing them down is considerably easier even with poor access.

[BadQ45t]

wow, first Y33 with over 200k that I have heard of....I'm nursing mine now with my X-Terra taking most of my miles (with 87 octane gas thank you) so I guess I';m okay for now.

New cars really don't run much different after tune-ups. My last service my air filter was trashed and I really couldn't tell the difference.

[Q_SHIP]

wow, first Y33 with over 200k that I have heard of

Im not far behind him.

[bullittandy]

Just an addition to clarify differences between model years. I just replaced the O2 sensors on my 99 and it was MUCH easier, nothing had to be removed and they are easily accessible.

Not sure of the switch in the position but if you've got a 97 then prepar for a touch job and if 99 or later then its easier.