O2 Sensor- 1998 Toyota Avalon

Hi all- My 1998 Avalon was recently diagnosed as having a failing oxygen sensor. I asked for the code, and my mechanic indicated that PO 135 came up. He is asking $400 for parts + labor, and I’m shopping around for a few more estimates. In the meantime, I’ve read that this might be something that I’m able to do myself. I’m not particularly mechanically-inclined (oil changes are about the extent of my experience), and would need to buy the necessary tools. Would it be worth my while to attempt this myself, or should I suck it up and pay a mechanic? Thanks for your help!

You’ll need a special socket to remove the O2 sensor, and after ten or more years they can be rusted in REALLY tightly.

Depending upon which O2 sensor you’re talking about, reaching it may be difficult.

It’s your call. I have the socket, but I’d want to see where it is before I decided to try it myself. I don’t like working on exhaust systems while lying on a concrete garage floor under a raised vehicle. Too much rust in the eyes.

And if you’re going to crawl under your Avalon, make sure it’s supported by jack stands or ramps.

P0135 refers to “bank 1, sensor 1”. That’s the sensor on the exhaust nearest the firewall, upstream from the catalytic converter. It’s tricky to get access to that sensor on a V6 Toyota of that vintage when on your back on a garage floor.