[eheiberg]

The check engine light has been on my 2002 four cylinder Saab 9-5 linear for a long time (several thousand miles). I just took the lovely car to the mechanic. He told me that I need a new Catalytic converter to the tune of $900. He just read the codes off of the computer and did not even check the car...he told me that there are 2 Oxygen (O2) sensors in the exhaust, but could not tell me accurately where the exhaust of the engine is located (front of the engine, not the back, where he said it was). Needless to say my confidence in him was lowered considerably. I don't think he even looked at the possibility that the sensors might be bad.

How can I be sure that it needs a new CAT and not just a new O2 sensor or two?

Any help is greatly appreciated.

Eric

 

[mecgmecg]

What are the codes he pulled from your computer?

 

[ji5mmy]

Find out which code(s) the CEL is spitting out.

P0420 is what I got for quite a while, which the code reader says means low catalyst efficiency. The code clearly says the cat is bad, except, that code really means that the difference in reading between the front and the rear O2 sensors isn't up to snuff. So, the front O2 sensor may be fouled, the rear O2 sensor may be fouled, or the cat may be gone.

In my case, I got tired of resetting the code every few hundred miles, so I replaced both O2 sensors. They sure are less expensive than a new cat, and I would say is the likely problem, based solely on experience and no expertise whatsoever.

 

[8pack]

Here is all you probably need to know....

http://www.saabcentral.com/forums/showthread.php?t=214539&highlight=p0420

Read the WHOLE thread below. Pay attention to my posts of course and the last post, those most likely address your problem...short story, Fix in this order:

J16 repair - free if you have the incination, otherwise find a buddy with some electrical repair knowledge.
non fouler - cheap and cheerful almost always does the trick
Both 02 Sensors (I have a brand new one if you want it)
CAT (UNLIKELY it is the cat)

http://www.saabcentral.com/forums/showthread.php?t=224608&highlight=p0420&page=2

here is the link to do the non fouler repair. It is from the Volvo site where i did it in my XC70 but same thing for saab.

http://www.volvoxc.com/forums/showthread.php?t=15359&highlight=fouler

 

[eheiberg]

Thank you for your replies. I am unsure of the codes that my mechainic got from the computer...I will ask. I will also try the fixes you suggested, 8 Pack. Thanks

 

[FK9-5SE2000]

Reading OBD Codes

Thank you for your replies. I am unsure of the codes that my mechainic got from the computer...I will ask. I will also try the fixes you suggested, 8 Pack. Thanks

One of your options if the mechanic will not give you the codes (why would he - he wants to get paid for the repair), is to go over to one of the local parts stores (e.g. AdvanceAuto). Generally, they have a code reader they wil allow you to use while they hold your driver's license. Often a good idea to call them first and confirm it is available. A few times, my local store's reader was damaged and not available and I had to go to the other one.

I finally got sick of having to go to them at all and bought one on the web, but that's an extreme step.

 

[Saaber95er]

Autozone would read them for you too; and give you a printout. If it's your sensor's it would be either bank 1 or bank 2 when read. If you consider getting your own code reader check out the torque app for android, it cost less than $30 to set up and you can read everything on your smart phone.

Thank you for your replies. I am unsure of the codes that my mechainic got from the computer Thanks

One of your options if the mechanic will not give you the codes (why would he - he wants to get paid for the repair), is to go over to one of the local parts stores (e.g. AdvanceAuto).