Checking CO Reduction

- Start engine and warm to operating temperature.
- Turn all accessories OFF.
- Connect CO meter to exhaust pipe.
- With the engine warmed up, keep engine speed at 1500--2000 rpm.
- If the CO concentration is 0.4% or less, the convertor is OK. If higher, refer to DIAGNOSIS, TESTING AND INSPECTION PROCEDURES / TESTING PROCEDURES / DIAGNOSIS BY SYMPTOM.