Toyota P0171 Code Reasons
4runner o2 P0420 fixed with replacing o2 and a/f sensors Toyota tacoma check engine light code p0420
P0420 fixed with replacing o2 and a/f sensors - Toyota 4Runner Forum
P0420 code tacoma toyota sensor downstream cel engine check light
![P0420 fixed with replacing o2 and a/f sensors - Toyota 4Runner Forum](https://i2.wp.com/i.imgur.com/YUqET65.jpg)