1994-2002 [Subscribe to Daily Digest] |
My original O2 sensor was good at 108K miles, when I changed it out for a generic three wire unit that I spliced in, saving a great deal of $$. When I changed it, the MPG and performance did not change. So I know the old unit was good. The 3 wire units can last a long time, but at over $200 ea, you want to be sure. Some vehicles have two O2 sensors, that can be big $$.
Your fuel filter should have been changed out near 100000 miles. I believe that they are good for substantially more that that, but if you have the original filter, time to change.
My usual list of basics to do before doing the dealer.
Replace your plugs, or inspect them at least. You do not have the Trionic DI ignition, you you do not need to stick to NGK plugs, but why not.
Note the color of the insulators on the plugs. If black, hard to say. They may be that way because of another problem. Uneven color across the cylinders is indicative of fouled fuel injectors and uneven fueling.
Use Techron Concentrate 2 or 3 times per year to keep injectors, intake valves and combustion chambers clean.
Air filter serviceable? If not, replace it.
After you run a tank with Techron in it, if you still have problems, then see the mechanic. If you find a profound improvement with the Techron, and you have not used such products routinely in the past, go for a second treatment.
If the plugs are fouled and or the mixture is uneven because of fouled injectors, the O2 sensor could be working ok but struggling with the other problems. The O2 senor closed loop feedback systems cannot be expected to work properly if the components are now working right. That includes things other than the O2 sensor itself.
Check the battery electrolyte level. Maintenance free batteries are a deception at best. Yes, this can affect engine ECUs.
Wipe down and clean the ignition cables, distributor cap, rotor etc, while you are doing the plug inspection regap or replacement.
Do the above as a process of elimination. Then you know where to focus your cash flow to get things fixed. Be sure to let the mechanic know what you have done as well if you need to go that route.
Note that the mechanic will replace your wires, rotor etc. This might be expensive. I have found that these can be washed in a sink of hot water and dish soap, rinsed, dried, baked at 200F for a while, cooled till warm, dressed with ArmourAll (the original), baked agian, cooled, wipe off excess ArmourAll. I have found that this is as good as new components, and the they can often last the life of the vehicle. Clean and treat the insulator of the coil, in place, as well.
Another basic is cleaning the throttle body. I don't know how you get the business over your throttle body off, but it is probably simple enought. Open the throttle plate by hand and swab things clean with a cloth with some solvent. You do not need a specialized cleaner, nor do you need to spray things down to move the dirt deposits into the manifold.
With your vehicles age and miles, you should also be watching for split ends on the vacuum lines. Some of them may be just plain rotten. Check also for some softening and swelling for the hose that attached to the valve cover which takes the crankcase vapors to the intake. If it does not fit tight anymore, you can help it out with some nylon wire ties.
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.
![]() |
![]() |
![]() |
![]() |
![]() |