Edmunds Answers



  • bandit10 08/07/08 12:29 am PST

    What makes you feel that your Cat. Conv. is bad? Is the engine not exhausting as well as it should or did? You can go to Autozone of other major parts retailer and they will scan your cars system free of charge. Because It could be a sensor or something else. If you start putting in and replacing parts with no results it gets expensive. Good luck, and leave feedback on your results and what the problem was. It benefits every one on this site.

  • tony78 08/07/08 1:48 am PST

    Esentially what your looking for is a restriction in the exhaust system.
    you did not mention what type of car that you had,,The first thing that would give you an indication of a restricted exhaust system is a loss of power,,this could include a rough idle and or stalling. When the engine is idling can you hear a rattling noise coming from exhaust system ? Can you smell exhaust vapors anywhere along the piping ? Where there are connections between the cat and the muffler is there evidence of black soot ? When you "rev up " the engine exhaust gasses being expelled from the tail pipe should increase. Older cars and trucks that used an air pump the dicharged air in to a fitting on the exhaust manifold allowed the mechanic to to remove the check valve and when they reved up the engine and if a lot of exhaust gas pressure came out of the fitting then this was a good indication that there was a restriction.
    You may need to remove the components and physically check the muffler and the cat(s) seperately,,When you remove the cat if any material falls out, there is a rattling sound when you shake it, you cant see a flashlight thru it, or it looks clogged you will need to replace it, The same basicly goes for the muffler except for the flashlight part. On a well maintained car/truck these parts should last about between 7-12 yrs +/- .
    I agree with bandit that the first thing you should check for is any stored codes as for replacing anything with the exhaust system could run you from $ 100.00 To well over several thousand dollars,,depending on the year,,make and model of your vehicle.

  • 0patience 08/07/08 9:25 pm PST

    Checking pressures at the inlet and outlet pipe of the converter is the best way to tell if a cat is restricted.
    See this article. http://www.troublecodes.net/articles/jd


Top Exhaust Experts View More

Rank Leader Points
1. MrShift@Edmunds 1745
2. karjunkie 1550
3. zaken1 1175
4. texases 660
5. thecardoc3 315
6. Stever@Edmunds 300
7. morin2 265