Changing O2's - not that bad

[Dr.Fiero]

Was flipping through my factory manual, looking for anything in the way of hints & tips on changing the O2's in my '98 STS.

Front was pretty straight forward.

Jack it up, slip under, move now lightly fried O2 wires off the manifold (darn previous owner!), remove, replace.

Rear on the other hand, they have you lowering the back of the whole darn cradle and reaching up!

What drugs were those guys on?!

I just looked down from the top... move the plug wires out of the way a tiny bit.

Used a long extension, and a proper O2 sensor crows foot socket. Bam! Done. 15 min's tops.

Oh, a good spritz of Lloyd's Moovit a few minutes beforehand on them, and having a very warm engine helps.

[OldFart]

I recently replaced both upstream O2 sensors on my 2003 DTS as well with similar results. The Deville is a little different setup and the FSM suggests getting the one next to the firwall from below too. I loosened it from the top too, only I used an O2 sensor socket which looks like an extra long spark plug socket with a slit cut into it. I used two extensions with a swivel joint in between them to clear the firewall. Broke the sensor loose but could not get my hand down on it from above to remove it, so I found crawling underneath the car and reaching up easier to remove the O2 sensor and hand tighten the new one. Final torquing of it from above with the socket.

This job was way easier to do than replacing the TCC Solenoid.

[the gold2]

Hey thanks for the tips!!

ought to be about same fire drill for the 4.9 liter engine...

[Big Big Al]

Last week I replaced both O2's on my 4.9 Seville (being a novice in Cadillac, I assume your motor is sideways also). I did not have the special O2 socket, but a closed end 22mm worked fine, because the plastic plug will fit thru the wrench hole with minor coaxing. Hand turn until tight, then wiggle the 22mm up the wired end, and torq the O2 in a smidge. You do not have much room to turn the wrench, but since it has twelve teeth instead of just six, it will fit the O2 easier. Actually, that last little torq to tighten could be done with a small vise-grip, but some on the system would faint if they heard me say that! Good luck.

[airmike]

Last week I replaced both O2's on my 4.9 Seville (being a novice in Cadillac, I assume your motor is sideways also). I did not have the special O2 socket, but a closed end 22mm worked fine, because the plastic plug will fit thru the wrench hole with minor coaxing. Hand turn until tight, then wiggle the 22mm up the wired end, and torq the O2 in a smidge. You do not have much room to turn the wrench, but since it has twelve teeth instead of just six, it will fit the O2 easier. Actually, that last little torq to tighten could be done with a small vise-grip, but some on the system would faint if they heard me say that! Good luck.

Sure glad I didn't hear you say that!