2016 Toyota Sequoia Check Engine Light in Murray, UT

It means the OBD-II system stored a fault code such as P0440 (EVAP) or P0300 (random misfire) identifying the affected system.

Your 5.7L V8 uses sensors and control modules to monitor emissions and performance; when a fault is detected, the Malfunction Indicator Lamp turns on. A loose fuel cap, vacuum leak, misfire, or catalyst efficiency issue can all trigger it. Our Murray service team reads the code and freeze-frame data, then verifies the cause before recommending repairs.

• Codes point to a system (EVAP, ignition, fuel, catalyst), not a guaranteed part
• Toyota Techstream access allows module-specific data beyond a generic reader
• Schedule service for a definitive diagnosis

Frequent causes include O2 sensor faults, EVAP leaks (loose gas cap), MAF sensor issues, cylinder misfires, or a failing catalytic converter.

The Sequoia’s V8 can set codes like P0420 (catalyst efficiency), P0171 (system too lean), or P0442 (small EVAP leak). Some issues are simple, but misfires left unchecked can overheat and damage the catalytic converter. Our Murray dealership isolates the true cause so you fix the problem, not just the symptom.

• Inspect gas cap seal and tightness after refueling
• Watch for rough idle, hesitation, or reduced power (misfire clues)
• Use OEM diagnostics to avoid unnecessary parts swapping

A steady light means drive cautiously to service, but a flashing light signals an active misfire and you should stop to prevent catalytic converter damage.

If the light is steady and the Sequoia drives normally, reduce load and plan a prompt inspection in Murray. A flashing MIL indicates raw fuel may enter the exhaust, risking costly catalyst damage. Use our online scheduler to reserve a diagnostic slot and review service specials before you arrive.

• Steady MIL = non-urgent but schedule soon; flashing MIL = urgent
• Avoid towing or high loads until checked
• Schedule an appointment for same-visit evaluation when available

Parts stores read generic codes; our Toyota Techstream and factory test procedures pinpoint the root cause with OEM data.

A code like P0171 (lean) can stem from unmetered air, fuel delivery, or sensor drift—only proper isolation testing confirms which. Our OEM-certified technicians in Murray access manufacturer data, perform smoke/pressure tests, and provide a written estimate before repairs. That accuracy helps prevent repeat visits and unnecessary parts.

• Factory scan-tool access, TSBs, and guided diagnostics
• Isolation testing verifies cause before parts are replaced
• Clear, written findings with repair options

No—clearing codes sets readiness monitors to Not Ready, which fails Utah emissions until the monitors complete.

Inspection stations check both for stored trouble codes and for OBD-II monitor readiness. If you recently cleared the light without fixing the cause, the Sequoia’s monitors won’t be Ready and the test will not pass. Correct the underlying fault and drive normally so monitors can run and set to Ready before retesting.

• Fix the cause, then allow monitors to complete before inspection
• Pending codes can turn the light back on during the drive cycle
• Need help? Schedule service for a readiness check

A flashing MIL indicates an active engine misfire severe enough to risk catalytic converter damage.

On the 5.7L V8, an ignition or fuel fault can let unburned fuel reach the catalyst, overheating it. Safely pull over, avoid heavy throttle, and arrange a tow if the light continues flashing. Our Murray team can diagnose coil, injector, or compression-related causes and advise next steps.

• Do not continue driving under heavy load with a flashing MIL
• Possible codes: P0300–P0308 (misfires)
• Use online scheduling for rapid diagnosis

For a thorough result on a 2016 Toyota Sequoia, our diagnostic follows a clear, step-by-step path. First, we perform an OBD-II scan and capture freeze-frame data to see the exact conditions when the fault set. Next, a visual inspection verifies basics like connectors, vacuum lines, and the fuel cap. We then run isolation testing (smoke/pressure checks, circuit tests, live data analysis with Toyota Techstream) to confirm the root cause. Before any repair, you receive a written estimate with options. Warranty work typically requires a certified facility, which protects your coverage. Review current service specials and schedule service online for your preferred time.

Larry H. Miller Toyota Murray serves the Salt Lake Valley and Greater Salt Lake City area—including Murray, Salt Lake City, Sandy, West Jordan, South Jordan, Millcreek, Holladay, and Taylorsville. Dealer-level diagnostics matter: our factory-trained, OEM-certified technicians use Toyota Techstream to access manufacturer data, bi-directional tests, and guided workflows that generic readers can’t provide. Seasonal temperature swings and daily driving can trigger EVAP or cold-start related codes; accurate testing distinguishes a loose cap from a system leak or sensor drift. We’ve been serving Utah drivers since 1979 at 5650 South State Street, Murray, UT 84107. Have a light on in your 2016 Toyota Sequoia? Call, stop by, or schedule your appointment online. For directions and additional services, visit our main Service Center page.

Several codes are frequently seen on the 2016 Toyota Sequoia. P0440/P0442 (EVAP) often relate to a loose or worn fuel cap or small system leak; ignoring them can lead to a failed emissions test. P0171 (system too lean) may stem from unmetered air or fuel delivery issues; left unresolved, it can cause drivability problems and misfires. P0300–P0308 (misfires) risk catalyst damage if driven under load. P0420 (catalyst efficiency) can indicate a failing converter or upstream sensor accuracy concerns; deferring repairs can increase costs. For clarity, we verify the fault with smoke tests, live data, and Toyota-specific diagnostics. Bring your 2016 Toyota Sequoia to Larry H. Miller Toyota Murray in Murray for an accurate diagnosis — schedule service.