Let’s break down the essentials for repairing the 1AZ-FSE.

: The engine is generally reliable, often reaching 200,000–250,000 miles with proper maintenance, though the cylinder block is typically not considered rebuildable by Toyota standards. Where to Find the Manual

| DTC | Description | Probable cause | |-----|-------------|----------------| | P0171 | System too lean (Bank 1) | Clogged injector nozzle, low fuel pressure | | P1229 | High-pressure fuel pump malfunction | Pump solenoid, fuel spill valve | | P1270 | Injector circuit open / short | Injector coil resistance out of range | | P1300 | Igniter circuit fault | Ignition coil, wiring |

: High-pressure fuel pumps and injectors are susceptible to fuel quality. Periodic cleaning of the intake manifold and injectors is recommended to combat carbon deposits ("coking") that impair spray patterns. Oil Consumption