Review on 🔥 Denso 234-4205 Oxygen Sensor - Exceptional Performance to Enhance Fuel Efficiency by Alex Tinker

Check Engine Light On. Plug in an OBD code reader and it says P0171, indicating the fuel system is running lean or rich and there is likely a problem with the O2 or MAF sensors. I removed the mass air flow sensor (next to the air filter) and cleaned it with a cleaning spray - nothing changed. Called a Toyota dealer to get prices for O2 sensors and was told that a 2000 Corolla has 2 sensors, one on the exhaust manifold and one next to the catalytic converter. I also found that most often the exhaust manifold fails. Prices researched online. Found on Revain.com; It was a lot cheaper than the dealer and other auto parts sites. It was an exact OEM for my machine so no adapters were required. I just removed the two mounting screws, took out the old sensor, put that in, replaced the screws and reset the check engine light (by removing one of the battery posts) and solved the problem. Do not recommend cheaper universal blocks with adapter plates that may not work.