I have a 1997 993 turbo with 17,000 miles which was driven little while in storage for about 5 years. Battery was replaced and car now runs fine, but I'm told the sensors have to be reset before it will pass state inspection. There is a protocol for driving that is supposed to do this, but two garages, including a Porsche dealer, have failed to get the sensors operational by this method. Is there another solution? I'm told I may have to replace the car's computer for $2,400.

 

I have used the below twice inorder to set the readiness codes;

Here’s "the cycle"

1) Start cold engine and idle for approximately 2 minutes, 10 seconds. This checks secondary air injection and evaporative leak detection systems.
2) Accelerate to 20-30 MPH and maintain steady speed for 3 minutes, 15 seconds. This establishes closed loop oxy-sensor operations, response times & switching times.
3) Accelerate to 40-60 MPH and maintain steady speed for 15-20 minutes. This evaluates catalytic converters while oxy-sensor response and switching times are checked.
4) De-accelerate and come to a stop. Idle for 5-6 minutes. This checks evaporative leak detection system.
Remember:
The diagnostic checks above will be discontinued if:
1) Engine speeds exceed 3000 RPM
2) Large fluctuations in throttle position
3) Road speeds exceed 60 MPH

 

Thank you very much for this information. The system is now working and the car inspected. Harold

 

Good deal!