Perform a visual and functional emissions system inspection to verify proper operation of all emission control components and check for leaks or damage.

Warnings

Tools required

Preparation

1. Park vehicle on level surface and apply parking brake
2. Ensure engine is cold before beginning inspection
3. Have vehicle registration and previous inspection records available for reference
4. Verify vehicle has been driven sufficiently to complete OBD-II readiness monitors

Procedure

1. 1

   Connect OBD-II scanner and check for diagnostic codes
   Locate the OBD-II diagnostic port under the driver's side dashboard. Connect the OBD-II scanner and turn ignition to ON position without starting engine. Retrieve any stored diagnostic trouble codes (DTCs) and note all pending or confirmed codes. Check readiness monitor status to ensure all emissions monitors have completed their drive cycles (at least 6 of 8 monitors should show 'ready' status for 2015 model year).
2. 2

   Inspect gas cap and fuel filler neck
   Remove the fuel filler cap and inspect the cap gasket for cracks, deterioration, or damage. Check that the cap clicks at least 3 times when tightened. Inspect the fuel filler neck for corrosion, damage, or deformation. Use a flashlight to look inside the filler neck for any obstructions. Reinstall cap securely.
3. 3

   Inspect evaporative emission control system
   Open hood and locate the charcoal canister near the fuel tank area (typically near rear driver's side). Inspect all EVAP hoses and connections for cracks, deterioration, or disconnection. Check the purge control solenoid valve mounted on the engine for secure mounting and intact electrical connector. Verify no visible damage to EVAP canister or mounting brackets.
4. 4

   Inspect air intake system and PCV system
   Inspect the air intake duct from air filter housing to throttle body for cracks, tears, or loose connections. Check all clamps are secure. Locate the PCV valve on the valve cover and verify hose connections are intact and properly seated. Check for any oil leaks around PCV system connections that could indicate malfunction.
5. 5

   Inspect exhaust system components
   Starting from the engine, visually trace the entire exhaust system to the rear of vehicle. Inspect exhaust manifold heat shield for damage or loose mounting. Check catalytic converter for external damage, dents, or discoloration indicating overheating. Inspect all exhaust pipe joints and hangers for leaks, rust-through, or separation. Look for black soot deposits indicating exhaust leaks.
6. 6

   Inspect oxygen sensors and wiring
   Locate the upstream oxygen sensor before the catalytic converter and downstream sensor after the converter on the exhaust pipe. Inspect sensor wiring harnesses for damage, melting, or contact with hot exhaust components. Verify electrical connectors are fully seated and locking tabs intact. Check that sensors are securely threaded into exhaust without excessive rust or corrosion.
7. 7

   Check EGR system components
   Locate the EGR valve on the intake manifold. Inspect the EGR valve for carbon buildup around the mounting flange and check electrical connector is secure. Verify EGR valve mounting bolts are tight and gasket is not leaking (look for carbon residue). Check any vacuum lines or coolant hoses connected to the EGR system for damage or disconnection.
8. 8

   Inspect crankcase ventilation system
   Check the PCV valve hose from valve cover to intake manifold for cracks or deterioration. Inspect the breather hose from valve cover to air intake for damage. Look for excessive oil residue in hoses which may indicate PCV valve failure. Verify all connections are tight and properly routed away from hot engine components.
9. 9

   Final visual inspection and documentation
   Perform a final walk-around inspection under the vehicle looking for any fluid leaks, damaged emission components, or missing heat shields. Clear any non-essential diagnostic codes if repairs were completed. Document all findings including DTC codes retrieved, readiness monitor status, and condition of all inspected components. Note any recommendations for future service.

Reassembly

1. Ensure all access panels and engine covers are properly reinstalled
2. Verify fuel cap is securely tightened
3. Disconnect OBD-II scanner and close driver's door

Verification

• Confirm no diagnostic trouble codes are present or all codes have been addressed
• Verify readiness monitors show sufficient completion for emissions testing requirements
• Ensure no visible exhaust leaks, damaged hoses, or loose connections remain
• Start engine and listen for any unusual exhaust noises indicating leaks
• Confirm MIL (check engine light) is not illuminated with engine running

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