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Carbon Monoxide Content: Testing

NOTE: DO NOT take measurements while radiator cooling fan is operating.
    NOTE: If the adapter has been used for fuel system testing, DO NOT use it for emission sampling. Residual fuel traces will make CO/HC readings inaccurate.
  1. Connect (VAG 1363) CO tester to CO tap tube, near Heated Oxygen Sensor (H02S), using adapter (VAG 1363/3). See Fig 1.
  2. Start engine and let idle. CO content must be 0.5-0.9 percent. See IDLE SPEED & CO LEVEL  table.
  3. NOTE: Failure of one spark plug increases CO content significantly.
  4. If NO: Ensure that all spark plugs are operating properly.
  5. If spark plugs are Okay, but CO is still NOT to specification, perform the following steps:
    • Read DTC memory again.
    • Initiate Output Diagnostic Test Mode (DTM). See OUTPUT DIAGNOSTIC TEST MODE in SELF-DIAGNOSTICS .
    • Check engine Basic Setting values in display channel 3 (display field, oxygen sensor).
  6. Make the necessary repairs.
Fig 1: Connecting Carbon monoxide Tester To CO. Tap Tube (Port)
G00177375Courtesy of AUDI OF AMERICA, INC.
IDLE SPEED & CO LEVEL

Application Idle RPM CO Level
2.22L Turbo
Man. Trans. (1) 770-830 0.5-0.9%
(1) Trans. in Neutral. Radiator cooling fan clutch not engage.