Smog ODBII Not Ready

[eddiesnellson]

I have a 97 SL and I recently had the MAP Sensor replaced prior to needing a smog check. I was told to drive it around for a few days, so I drove it around for a week and the check engine light came back on.

Then I had the throttle position sensor circuit replaced. Again, I was told to drive it around for a while before taking it to smog. I continuted to drive it for another week and the light stayed off, so I took it to get smogged and it failed the OBD self check, but passed emissions. The smog place told me to keep driving it around for a while and to bring it in hot next time.

So I did that, I even looked up the cycle engine driving instructions and have been trying all those things. I drove it for a few hundred more miles, on both the freeway and streets, then I took it back today and it still is "not ready" for the Catalyst, Oxygen Sensor, and EGR System Monitors.

I did some research on the forums here and saw a few posts with similar problems. Someone mentioned that the thermostat might be an issue in letting the OBDII run it's checks, if it is running low then it never runs those checks. Does that sound right? My engine seems to run at just over 1/4 on the temperature gauge, is that too low? Does anyone have any other suggestions besides "drive it around for a while" before I go ahead and get the thermostat replaced?

[Cheyne]

The temp gauge is reading too low.

Has the ECTS (engine coolant temperature sensor) been replaced?

If not, you need to replace it and check the connector for corrosion. After that, if it is still at 1/4, replace your thermostat with an 87C or 195F. The temp gauge needs to read approx 3/8.

After that, the tests should complete.

Go to the how to forum. The first sticky is the richpin videos and one has the ECTS replacement. The second and third stickies deal with the ECTS also.

Welcome to the forums!

[OldNuc]

After you get the temperature up you will need to walk throughthe drive cycle if you are on a short time schedule for a smog test. Skip the electrical loat portion of #2.