It would be very nice if this site had a FAQ page. I've searched for this information for some time now and finally found it so I'm posting it here. I assume this information is the same for first generation 70 series Volvo's too:


If you are having trouble getting your 850 through state emissions test and the source of your frustration is ‘readiness’ codes that aren’t set, the following procedure from Volvo will help set the readiness codes.

Start with the vehicle cool, below 122 degrees F.
Turn off the air conditioning.
Select a location where the driving can be done without violating traffic laws and you can stop safely at the side of the road.

1. Start the engine and accelerate to approximately 1500-2000 rpm.
2. Drive for 6 minutes at 1500-2000 rpm.
3. Stop the vehicle and remain at idle in drive for 70 seconds.
4. Accelerate to at least 45mph and drive for 5 minutes at 1800-2200 rpm.
5. Stop the vehicle and remain at idle in drive for 60 seconds.
6. Accelerate to at least 45 mph and drive for 4 minutes at 1800-2200 rpm.
7. Stop the vehicle and remain at idle in drive for 60 seconds.
8. Park the vehicle and turn off the engine.

This procedure must be performed TWICE from a cold start to set the readiness codes.
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1998 S70 T5 Emarald Green Metallic, 2004 V70 2.5T Ruby Red, Previous Owner of Black '94 850 Turbo Wagon. My cars have been running so well lately they've got me worried.