Under certain conditions, some 2005-2006 Toyota 4Runner vehicles may exhibit a MIL ON condition with at least one of the following DTCs:
The air-fuel sensor manufacturing process has been improved to correct this condition. Applicable vehicles include 2005-2006 models produced before the following production change VINs:
ENGINE PRODUCTION CHANGE EFFECTIVE VIN
Sensor, air fuel ratio……..89467-71020 (new part uses same P/N as new part)
Refer to the Technical Information Service (TIS), 2005-2006 model year 4Runner repair manual: Diagnostics: SFI System (applicable engine): P0171, P0174; or P2195, P2197. Only replace the A/F sensor indicated by the MIL ON DTC(s).