2015 Scion FRS 2.0 P0171, P117B, P1170 Lean Bank 1

Summary

Robert Dotterer, an automotive technician at Dotterer’s Auto Service, diagnosed a 2015 Scion FR-S with P0171 (lean Bank 1), P1170 (port-injector fuel performance), and P117B (direct-injector fuel performance). He used a Launch scan tool with Toyota/Scion coverage and an eSCAN tool to review and graph live data.

Fuel trims looked mostly reasonable during the drive, but the freeze-frame data showed nearly 49% fuel trim when the fault set. The codes alone did not establish whether the port or direct injection system was responsible.

Inspection revealed an aftermarket warm-air intake with electrical tape near the mass-airflow sensor (MAF). A smoke test showed smoke escaping around the MAF and taped connection, indicating a poor seal. Directing air at that area also affected fuel-trim readings, supporting the possibility that airflow around the sensor was skewing its readings.

Likely cause: A leak or poor fit at the intake/MAF connection, rather than a confirmed injector or electrical fault. The technician planned to clear the codes and retest. The customer said replacement intake piping was already on the way, but the video does not show a final repair confirmation.

Diagnostic Workflow

The video demonstrates a diagnostic process of scanning codes and live data, reviewing freeze-frame information, inspecting the intake, smoke-testing for leaks, and observing fuel-trim changes. It does not present a product review.