Tail Pipe Test

Typical causes for failing a tailpipe test include:

• Air to fuel mixture may be incorrect.
• Positive Crankcase Ventilation (PCV) valve may be malfunctioning or missing *
• Vacuum leak present
• Exhaust Gas Re-Circulation (EGR) may be malfunctioning *
• Ignition timing may be incorrect
• One or more worn, damaged, or fouled sparkplugs are present
• Catalytic converter is clogged, missing, or ineffective *
• Malfunctioning oxygen sensor
• Internal engine parts may be malfunctioning or damaged
• Dirty or contaminated engine oil
• Clogged air filter

*Indicates items that may or may not be standard equipment

OBD Test – 1996 and newer vehicles are tested by checking the vehicle OBD system (the vehicle’s computer) for problems. Causes for failing an OBD test:

• The vehicle’s on-board diagnostic system reports a failure or problem with an emissions related component or sensor. If there is a problem, the “Check Engine” or “Service Engine Soon” light may be on. If the light is on when you come in for inspection, the vehicle will fail the test.
• The Check Engine light is malfunctioning.
• The diagnostic connector is missing, damaged, or not functioning.
• During battery replacement or vehicle repair, the vehicle computer’s memory is reset.
• If your vehicle has failed for being “not ready” and you have been operating your vehicle regularly, consult a repair technician before retest.

The VIR will provide specific reported trouble codes (up to 5 total when applicable) to further aid your mechanic in diagnosing and repairing the vehicles emissions systems.

Visual Catalyst Inspection

All gasoline-powered vehicles 1975 and newer and less than 8501 lbs. gross vehicle weight will receive a visual catalyst inspection. Vehicles will fail the visual inspection if the catalyst is missing or has been tampered with. The catalyst must be repaired prior to re-inspection.

Gas Cap Inspection

Typical causes for failing a gas cap functional test:

• Gas cap leaks.
• Gas cap is non-removable or missing.

In most cases, simply replacing the old or missing gas cap with a new one will allow the vehicle to pass this portion of the test.