7M-GTE Bucking/Misfiring Under Throttle - Faulty AFM (Air Flow Meter)

Fuel Systembeginner✓ OP Confirmed

Problem

7M-GTE engine bucking and misfiring under throttle at various RPM ranges and throttle positions. The issue felt similar to fuel cut and ranged from small misses to severe repeated bucking in a single gear.

Engine bucking/misfiring under throttleMisfire concentrated around 3000-3500 RPM and 4500-5000 RPMOccurs at any throttle position percentageFeels similar to fuel cut but slightly softerIntermittent severity - sometimes small miss, sometimes 4-5 bucks in one gearSmooth at very light constant throttle tip-inEngine pulls strong between misfire episodes

Root Cause

Faulty AFM (Air Flow Meter / Karman Vortex sensor) sending an incorrect or degraded signal to the ECU, causing intermittent loss of proper fuel/air metering under load. The AFM electronics can wear out over time and produce a poor signal that doesn't trigger diagnostic codes but causes drivability problems.

Confidence

High confidence — Original poster confirmed this resolved the issue

View Original Thread →Posted September 2022 on SupraForums.com