Comments on: How to Tune an Eight Valve Saab 900

on 1/16/2006 Don't disconnect your 02 sensor while testing it. The oxygen sensor is a device that is used to trim the air/fuel mixture as close to stoichiometric as possible. With the 02 sensor disconnected the controller will not receive the correct inputs, and depending on the air fuel mixture being too lean, you may not get a voltage signal from it. With the sensor connected, put your voltmeter ground side on the battery and your positive lead on the voltage signal from the 02. While the engine is running in closed loop operation (feedback mode), if your vehicle is running properly, you should see a voltage fluctuation of .2V-.8V.
.5V is the mean value indicating a perfect fuel mixture. Above .5 is rich and below .5v is lean. The only way to verify if the 02 is calibrated correctly is to have a gas machine measuring the actual 02 emissions from the tailpipe.

on 12/9/2005 Go for nothing less than a Bosch distributor and rotor arm, they're original equipment and best quality.
Same with spark plugs and leads, NGK and Bougicord.
Don't let the people at Eurocarparts or GSF fob you off with other makes of spark plug, my 900's have always run best with NGK's.
Once, at Eurocarparts upon checking the paper work, I'd noticed my Saab had been typed in as a 9000. I insisted that a 900 be typed in to check the codes of the bits that I had ordered. The guy didn't want to do it, another more helpful body behind the counter did it and sure enough, all the codes changed.