O2 sensor location on GM 3400

[pwm72]

I have a 2003 Buick Rendezvous and have a SES light on. Took it to Autozone to check the code and it indicates O2 sensor in #1 position. I guess there are two sensors. Does anyone know the location of these sensors and are they relatively easy to change? My car has 95,000mi on it and I may as well replace them both. While I am at it I will replace the spark plugs. What is the recommended replacement plug and at what gap?

Thanks in advance. I tried searching on the O2 sensor location and came up empty.

Thanks
Paul Manuel
Elkton, MD
pwm72@comacast.net

[sprucegagt]

The "first" O2 sensor (B1S1) is located in the rear exhaust manifold and the "second" sensor (B1S2) is located just after the catalytic converter. Stock plugs should be a good replacement with gap at .060.

[pwm72]

Thank you Spruce, now the $64,000 question... What is the easiest way to get to B1S1 as well as the rear plugs? From the bottom? I can't see how to get to the rear of the engine from under the hood.

Thanks again for the response.

Paul

[Alxsmt]

in my car i just find it easiest to remove the coils/ICM bracket (i wanna say its 4 13mm bolts, 2 on the plenum and 2 on the head) and that should make enough room to get the plugs out from the top, its a tight fit still. im guessing it would be the same on your car but you may have some plastic to remove too

[pwm72]

great information, thank you very much. Glad I found this site, it seems full of helpful people.

[pwm72]

Changed my plugs and wires today

Well, finally got around to changing the plugs and wires today on my 2003 Buick Rendezvous. What an ordeal!

Why do they have so much engine set-back on these things? I had to remove the front dog bones, remove the coil pack and put a rachet strap on the front of the engine (thankfully they have a cast bracket that looks like it was made just for this purpose) and around a pole in my garage. I also had to drop the exhaust as it was not allowing enough movement of the engine forward. Thankfully the exhaust was only two bolts and the easiest part of the job.

Naturally, my local auto parts store did not have any AC-Delcos in stock, so I stayed away from the Bosch that they were pushing and couldn't see spending the cash for the Denso's so I ended up with Autolite APP606's and Borg Warner wires.

The rear plugs were a bear to get in even with all of the engine movement, but it's done now and seems to run a bit smoother.
Thanks again for the advice guys...I appreciate the guidance I had received.