Toyota and Lexus Firmware 89663-60731: 2UZ-FE Engine Calibration

89663-60731 is an engine-control calibration associated with the Lexus LX470 and its 2UZ-FE V8. Related catalog filenames also identify the GX470. The engine control module uses calibration data to manage engine operation, including emissions-system monitoring. One group of modified files for this identifier is labeled for secondary air injection, or SAP, removal from the calibration.

Secondary air injection and the SAP OFF files

The secondary air injection system helps reduce exhaust emissions after a cold start. It pumps fresh air into the exhaust stream so the catalytic converters can reach effective operating temperature sooner. The engine control module commands the system and monitors its operation as part of its emissions strategy.

The catalog includes an LX470 2UZ-FE file named 89663-60731_SAP OFF FULL_736kb_CRC OK and several files labeled MOD_sap_off_e2, including GX470 and LX470 variants. The SAP OFF label describes a modification intended to disable the calibration’s secondary air system functions or monitoring. It does not establish exactly which checks or control routines were changed.

The e2 suffix appears in the modified filenames, but the names do not explain what it changes. Likewise, CRC OK is a catalog claim about the file’s checksum, not evidence of vehicle compatibility or emissions compliance.

EVAP-labeled variant

A separate GX470 file is named SW#89663-60731- MOD_EVAP_и прочее.bin. EVAP refers to the evaporative emissions system, which contains fuel vapor and routes it to the engine for combustion under suitable conditions. The Russian phrase и прочее means “and other things.” The filename identifies an EVAP-related modification but does not describe the individual changes, and it should not be treated as the same modification as the SAP OFF files.

These filenames describe modified variants rather than a documented stock revision history. The identifier connects them to a common software record, while the vehicle and variant labels help distinguish the listed files. The names alone do not establish interchangeability between vehicles or the effects of every modification.