Three months ago the CEL turned on. Took it to the dealer, and diagnosed the problem as Camshaft position sensor magnet. The dealer replaced all four magnets and cleared the CEL codes. Now, I need to get the car smoged in California. However, since that repair was completed, the drive cycle is not ready for O2. I tried to follow the instructions several time, but no success. I drove the car for more than 1000 miles and it is never complete. No codes either. Any advice???

 

Is the CEL still on?

you can clear the stored codes that are causing it with a mb compatible scan tool without resorting to a lengthy drive cycle.

 

No, the CEL is not on. I cleared all codes, and the OBD does not show any codes, but the cycle never completes. The O2 is still flashing, indicating that this is the only test not complete. The problem is that I drove the car for more than 1000 miles (free way and surface streets) and still not complete.

 

Which malfunction indicator is blinking?

 

This is what I am getting on my OBD scanner for a couple of month. No codes, no CEL, but the O2s is still red and blinking indicating the cycle is not complete.

 

have you hooked it up to an actual MB star /das system?

 

Take the vehicle in and get it tested anyway. If nothing else, it will confirm whether your obd scanner readings are correct.

Also, try adding a fuel additive such as a fuel injector cleaner (STP?) to see if the increased fuel efficiency triggers the tests. I typically complete 2 consecutive treatments/tankfulls before an emissions test on any vehicle with an O2 sensor code.

 

No, I have not.

 

I have two OBS scanners. It is reading correctly.
Some suggested replacing the Oxygen sensors (lazy sensors), but am not quite sure if this is really the problem.

How is the fuel injector cleaner going to help with the O2 sensors?

 

Fuel Injector cleaners work by removing carbon deposits from your injectors and other fuel system components (including the O2 sensors). Of course, you could simply replace the sensors.. but that is not your problem. If I understand you correctly, you are trying to trigger the O2 tests.

If the sensor detects a significant change in the exhaust composition it might be enough to trigger the test.

 

Sounds good. I will use a fuel injector cleaner and will keep you posted if it worked. Thank you!

 

I think the main question here is; will the test station get the same reading as you have?

only one way to find out.

 

Why would they have a different reading?