Review on 🚗 Enhanced Denso 234-4215 Oxygen Sensor by Tim Thomason

My check engine light was on and I got 3 codes on my 2003 Lexus RX300 AWD: P0171, P0174, P0136. I read online that p0171 and p0174 are related to a bad MAF (mass air flow sensor) and P0136 was the result of the previous two codes. So I ordered an air mass meter from Revain and installed it (very easy, about 10 minutes). But after 20 minutes of driving, all three codes came back. I then turned to code P0136 instead of the other two and read online that P0136 is the result of a faulty O2 sensor (B1S2 - Bank 1 Sensor 2). This sensor (Denso 234-4215) is an OEM replacement for my 2003 Lexus RX300 AWD Bank 1 Sensor 2. I ordered it, installed it (about 45 minutes - not too hard if the nuts holding the sensor aren't are too rusty.) and all codes have been cleared. I have now driven the car over 500 miles and the check engine light is still off. I took my car to an emissions test (which had previously failed) and it passed with no problems. I think replacing the O2 sensor instead of the MAF would have solved the problem in the first place, but I don't. I don't know it. It's possible that the MAF sensor needed replacing anyway (I keep telling myself that so I don't feel bad about spending $90 on it). Money without taking it to a mechanic.