Emissions Inspection

Perform a comprehensive emissions system inspection on the 2017 Maserati Levante 3.0L V6 Twin Turbo to verify proper operation of all emissions control components and ensure compliance with environmental regulations.

Warnings

Tools required

Preparation

1. Ensure vehicle has been driven at operating temperature for at least 15 minutes prior to inspection, then allowed to cool completely
2. Position vehicle on level surface with adequate ventilation
3. Verify fuel tank is between 1/4 and 3/4 full for accurate EVAP system testing
4. Gather vehicle service history to review previous emissions-related repairs
5. Ensure OBD-II scan tool is updated with latest Maserati software

Procedure

1. 1

   Connect Diagnostic Equipment and Retrieve Fault Codes
   Connect OBD-II scan tool to diagnostic port located under driver's side dashboard. Turn ignition to ON position without starting engine. Retrieve and document all stored diagnostic trouble codes (DTCs), pending codes, and freeze frame data. Check readiness monitors to ensure all emissions monitors have completed their drive cycles. Record number of warm-up cycles since codes cleared.
2. 2

   Inspect Catalytic Converters and Exhaust System
   Visually inspect both catalytic converters (one per turbocharger bank) for physical damage, heat discoloration, or signs of internal substrate failure. Check for rattling by gently tapping converters with rubber mallet. Inspect all exhaust connections, gaskets, and hangers from turbochargers to tailpipes for leaks, cracks, or corrosion. Verify heat shields are intact and properly secured. Check for any aftermarket modifications to exhaust system.
3. 3

   Inspect Oxygen and Air-Fuel Ratio Sensors
   Locate all four oxygen sensors (two upstream pre-cat sensors and two downstream post-cat sensors). Visually inspect each sensor for carbon buildup, oil contamination, or physical damage. Check sensor wiring harnesses for melting, chafing, or corrosion at connectors. With scan tool connected, view live data for all oxygen sensors while engine is running at idle and verify voltage cycling properly (upstream sensors should fluctuate 0.1-0.9V, downstream sensors should remain stable around 0.45V).
4. 4

   Test Evaporative Emissions (EVAP) System
   Inspect fuel cap for proper seal and verify tether is intact. Locate EVAP canister in right rear wheel well area and inspect for physical damage or saturation. Trace EVAP lines from fuel tank to canister to engine for cracks, disconnections, or damage. Check purge valve located near intake manifold and vent valve at canister for proper operation using scan tool active tests. Listen for purge valve clicking when commanded open. If available, perform smoke test on EVAP system to verify no leaks present.
5. 5

   Inspect Positive Crankcase Ventilation (PCV) System
   Inspect PCV valve integrated into valve cover and connecting hoses for cracks, oil saturation, or blockage. Check oil separator system for proper function. Verify intake manifold and turbocharger inlet hoses have no cracks or loose connections allowing unmetered air. Inspect both turbocharger wastegate actuators and vacuum lines for proper operation and no leaks.
6. 6

   Inspect Air Intake System and MAF Sensors
   Remove engine air filter and inspect condition. Replace if excessively dirty or oil-contaminated. Inspect air filter housing for proper seal and no cracks. Examine mass airflow (MAF) sensors located in air intake path for contamination or damage to sensing elements. Check all intake ducting from air filter to turbochargers for cracks or loose clamps. Verify no aftermarket intake modifications present that could affect emissions.
7. 7

   Inspect Turbocharger System Components
   Visually inspect both turbochargers for oil leaks at center housings, exhaust leaks at turbine housings, and boost leaks at compressor outlets. Check all intercooler piping and both intercooler cores for damage or oil accumulation. Verify bypass valves and diverter valves operate correctly. With engine running, listen for abnormal turbocharger noises indicating bearing failure. Check turbocharger oil feed and drain lines for restrictions or leaks.
8. 8

   Test Secondary Air Injection System (if equipped)
   Verify operation of secondary air injection pump if equipped for this market. Check air pump relay and fuse. Listen for pump operation during cold start. Inspect air injection check valves and connecting hoses for proper condition and no backflow. Verify air distribution to exhaust manifolds is functioning correctly using scan tool active tests.
9. 9

   Verify EGR and Emission Control Valve Functions
   Using scan tool, command tests for all emission control valves and solenoids. Monitor actual versus desired positions for throttle body, variable valve timing solenoids, and any EGR components. Check for proper response times and no mechanical binding. Verify no vacuum leaks at intake manifold gaskets or vacuum line connections that could affect emissions.
10. 10

    Review Fuel System Parameters
    With engine at operating temperature and scan tool connected, monitor fuel trim values at idle and 2500 RPM. Short-term and long-term fuel trims should be within ±10% indicating proper air-fuel mixture. Check fuel pressure readings are within specification. Verify no fuel odors indicating leaks. Inspect fuel injectors for external leaks or excessive carbon buildup on intake valves visible through throttle body.
11. 11

    Document Findings and Clear Codes if Appropriate
    Document all inspection findings, DTCs retrieved, and monitor status. Take photographs of any damaged components. If repairs were completed, clear diagnostic codes and perform drive cycle to verify all monitors complete successfully. Print final scan tool report showing no active codes and all monitors ready. If issues found, provide detailed report with recommended repairs and do not clear codes.

Reassembly

1. Reinstall any components removed during inspection ensuring all connectors are fully seated
2. Verify all engine covers and shields are properly reinstalled
3. Clear any fingerprints or debris from inspected components

Verification

• Confirm OBD-II scan shows no active DTCs and all readiness monitors are complete/ready status
• Verify no exhaust leaks audible during engine operation at idle and 2500 RPM
• Confirm fuel cap seals properly with no check engine light illumination after drive cycle
• Test drive vehicle and verify smooth operation with no emissions-related warning lights
• Document that all emission control components are present, unmodified, and functioning as designed

Related trouble codes on this vehicle

Codes that commonly send this job to the bay — tap one for symptoms, causes, and diagnostic steps.

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