Denso 234-9021 Upstream Heated Oxygen Sensor with 4-Wire Plug and 14.17 Harness Fits select: 2001 TOYOTA CAMRY, 2000-2004 TOYOTA AVALON

It's a genuine product, printed Denso logo on the product, also can be returned if not working within 30 days, local auto parts retailers are not returnable, great customer service. Before this purchase, bought a same one from a different site, the price was a lot cheaper but it was not working, it looked like a imitation piece, please don't buy cheap stuff, don't waste your time even refundable.

This Denso 234-9021 is an OEM oxygen sensor made for Toyota. Actually this should be called a fuel-air sensor rather than an oxygen sensor. I replaced the failed sensor with this one and corrected the P1130 and P1135 codes on my 2000 Toyota Avalon. There are 2 of these sensors on the 2000 Toyota Avalon, one is in the front near the radiator which is very easy to replace, probably 5-10 minutes. Unfortunately, I had to replace the one located just below the exhaust manifold toward the back of engine near firewall, which was painful to replace but doable. Just make sure to spray the old sensor with BP blaster for 30 minutes to an hour before removing it. This OEM sensor is more expensive, but I definitely would not buy any after-market sensors that often don't work or fit.