Fails Emissions Test

Check for leakage or blockage of vacuum lines.
Check for cooling system malfunction.
Check for spark plug malfunction.
Check for air leakage from intake manifold.
Check for erratic or no signal from CMP sensor.
Check for inadequate fuel pressure.
Check for PCV valve malfunction or incorrect valve installation.
Check for EGR valve malfunction.
Check for exhaust system clogging.
Check for fuel tank ventilation system malfunction.
Check for charcoal canister damage.
Check for air cleaner element clogging or restriction.
Check for throttle body malfunction.
Check for ignition coil or related circuit malfunction.
Check for Improper air/fuel mixture ratio control operation.
Check for excessive carbon built up in combustion chamber.
Check for improper engine compression.
Check for improper valve timing.
Check for catalyst converter malfunction.
Check for engine internal parts malfunction.