Honda Civic will not set the EVAP and Catalyst emission monitors

If your Honda Civic recently had its battery replaced (or had a dead battery and it was charged) or had it's emission trouble codes reset, you may very well need to drive it for a few hundred miles in order to trigger the readiness tests to run and set the EVAP and Catalyst monitors. The Catalyst monitor will run fairly quickly. The EVAP monitor might take some time. Insure your gas tank is always (and only) 1/4 to 3/4 full until the monitor runs. If after 300-400 miles of driving the monitors fail to run, there are no trouble codes present (check engine light is not on), you will need to have Honda (or a well trained smog check mechanic) manually attempt to trigger the readiness tests by following a very precise driving pattern ustilizing the smog station's dynomometer. If trouble codes are present (which are stopping the readiness tests from running) those trouble codes will need to be diagnosed.

posted by SmogTips Support

UPDATE: Honda Civic still won't pass SMOG due to EVAP and Catalyst readiness monitors not setting - passes all other tests. Took the car back in and had it checked again, same two not setting. The car had a new battery put in 4 years ago and to my knowledge the check engine light has never been on in the 6 years I have owned it. I have never had problems with it starting. We drove the car from Missouri to San Fran three weeks ago, which is about 2500 miles. Also I have been driving about 40 miles round trip a day in CA traffic, both on and off highway. I'm just trying to get as much info as I can before I take it in and waste money for them to tell me I need to drive it more. Is there anything I can do to help set those monitors? 2nd ANSWER: At this point we have to recommend you allow the dealership to diagnose the reason your Honda Civic's readiness tests will not run, and monitors not complete. Either the required parameters are not being met or there is a fault which is stopping the monitors from running (a fault which obviously is undetected by the ECU; or else you'd have an illuminated check engine light).

posted by SmogTips Support