What's the 2007 Toyota Yaris oxygen sensor location?

On the 2007 Toyota Yaris, You'll find two different oxygen sensors. There's an upstream O2 sensor that measures the air to fuELRatio, and it's located nearer to the vehicle's engine. There's also a downstream sensor that measures residual oxygen post catalytic converter; this is located on the exhaust pipe, predictably nearer to the rear of the Yaris than the catalytic converter. Both are relatively simple replacements, but they'll cost You significantly more to go through a mechanic; while the parts can be found as low as $20 for the downstream and $150 for the upstream, You can expect to pay between $200 and $450 through most repair shops. My recommendation, if You're confident enough, is to follow a good YouTube walkthrough and save a few dollars.