Resetting Cat monitor

[Gary Sanders]

02 996.2 C2. Using OBD II smog test passes everything, but Cat monitor shows not responding. I believe the drive cycle for this is: Maintain speed between 55-60mph for 15 mins, no braking. Is this correct? Are there additional steps or requirements?

[JFP in PA]

Welcome to RennTech 

If you are referring to the I/M Readiness test showing the cats are not ready, you may have a bigger issue.  The cats show ready when they meet certain electrical signal parameters coming from the O2 sensors:

 

If the cats do not meet this threshold, and the O2 sensors check out OK, one or both of the cats could be on the way out.

[Gary Sanders]

Great to know, but can you confirm the drive cycle is correct?

[JFP in PA]

1 minute ago, Gary Sanders said:

Great to know, but can you confirm the drive cycle is correct?

 

No.

[Ed Leed]

Here is the drive cycle that I found on the Rennlist forum.  I did exactly as this guy instructed, then drove to the EPA test station without shutting the engine off and passed with one failed item. 

 

From Rennlist:  I passed my smog test in AZ 1 hour after resetting everything, roughly 25 miles after it. What I did was FOLLOW the drive cycle procedure to the T. This is what I did. I cruised at low speeds on 19th ave in Phoenix to get the timing. And timed myself with a stopwatch.

 

DO NOT EXCEED 60 MPH AT ALL COSTS!!!

 

1.    Start engine, let idle for approx. 2 min, 10 secs.

 

2.    Accelerate to 20-30 MPH, Maintain steady speed for approx 3 min, 15 secs.

 

3.     Accelerate to 40-60 MPH, Maintain steady speed for approx 15 mins.

 

4.    Decelerate and come to a stop. Then:

Idle in Neutral for 5 mins. (manual trans.)

 

5.    Idle in Drive for 5 mins. (Tiptronic trans.)

During the drive cycle, do not exceed 3,000 rpm or 60 mph.

 

Don't shut off the car before smog test. That is what I did, and I had a constant SAI pump error triggering CEL. Car passed the test.