Exhaust System Should I replace the O2 sensor when I get my CAT replaced?

Discussion in '6th Generation (1997-2002)' started by Chunkylover53, Wednesday 12th Aug, 2015.

  1. Chunkylover53 Expert Advisor ★ ★ ★ ★ ★

    Judging by my MPG and used CAT prices I am thinking of replacing the O2 sensor (still working AFAIK) with a new one. Is it worth it for any possible gains in MPG/to save myself labour when it dies later?
     
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  2. i-DSI Expert Advisor ★ ★ ★ ★ ★

    Belgium Aalst
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    Not an easy question. But I would stick to the Honda workshop manual and I believe there's nowhere to be found that the sensor needs replacing when not diagnosed as broken.
    If it fails, you will have a DTC.
    Yes, you are right, an old sensor might (!) influence MPG. But not that dramatic because it always needs to operate in a quite tight window.
    Do you have the possibility to check the output of the sensor (is this car OBD, don't know by heart?). You need to see it give output going up and down all the time. If it keeps its output too long high or low, somthings' wrong.
     
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  3. exec Premium Member Club Supporter

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    I wouldn't bother, the one on the Cat isn't going to make a huge amount of difference and it would be waste disposing a working one and spending money on new one. If you want you can clean it, someone on TypeAccord forum cleaned their to improve MPG, but haven't yet reported the outcome.
     
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  4. Chunkylover53 Expert Advisor ★ ★ ★ ★ ★

    I wish I could but all I've got is the 5 pin connector, its an OBD2 car without a port.

    Interesting, never knew you could clean them. To be honest the only reason I considered changing the O2 sensor was after seeing 6th Generation CAT's go for £150+ on eBay so I may as well put it towards something else for the car.
     
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  5. jostree Senior Member ★ ★ ☆ ☆ ☆

    Portugal jostree Lisboa
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    I did clean my but it didn´t work.
     
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  6. Chunkylover53 Expert Advisor ★ ★ ★ ★ ★

    Thanks :Smile:
     
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  7. SpeedyGee Administrator Staff Team

    England Speedy Birmingham
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    I'd say a O2 sensor either works or it doesn't work. By working I mean it detects lean and rich swing and sends the appropriate voltage to the ECU.

    If it wasn't switching between lean and rich the ECU would flag up a O2 sensor error and thrown a CEL.

    Cleaning just gets rid of any soot that may have built up around the holes in the O2 sensor but again if the soot blockage was causing an issue the ECU would have thrown an error.
     
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  8. Chunkylover53 Expert Advisor ★ ★ ★ ★ ★

    Sorted, I'll give the o2 sensor change a miss for now then :Smile:
     
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  9. Chunkylover53 Expert Advisor ★ ★ ★ ★ ★

    I got a quote to get the CAT changed by a proper garage for £35 which seems reasonable considering that they'll let me keep the old one. Considering an aftermarket CAT ranges from £55-£85 it seems a no brainer.
     
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  10. exec Premium Member Club Supporter

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    That seems like a very reasonable price and I can't see why anyone wouldn't let you keep your cat? It is your property afterall.
     
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  11. Chunkylover53 Expert Advisor ★ ★ ★ ★ ★

    Got my CAT changed today, cost £36 for labour and £85 for the CAT itself. If you have a car built before 2001 you can purchase a cheaper type which costs £55 though I went for the security of passing emissions tests.

    I listed the old CAT on ebay and got an offer of £120 within 5 hours which basically covers my costs. I declined as they tend to sell for £150 but if you're on your original CAT I recommend ripping it out and selling it before it gets nicked.

    I bought the BM BM90962H model CAT
    If you want the cheaper version its model is BM BM90962

    Finally, after getting the CAT installed run the car for at least half an hour for the ceramic and mesh to fuse together (and various other things to happen) so the CAT works flawlessly come emission testing time. I ran mine for 45 minutes and covered around 55 miles in that time with plenty of speed and VTEC to really heat it up good.

    If you got any questions post below :Smile:
     
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  12. SpeedyGee Administrator Staff Team

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  13. Nels Moderator Staff Team

    :whathesaid:
     
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  14. Chunkylover53 Expert Advisor ★ ★ ★ ★ ★

    That averages at a titch above 70mph done in 3rd/4th to generate a lot of heat :Smile:
     
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  15. SpeedyGee Administrator Staff Team

    England Speedy Birmingham
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    Haha... I was actually disappointed with lack of pictures from the work carried out :Smile:
     
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  16. Chunkylover53 Expert Advisor ★ ★ ★ ★ ★

    Aha! It was done while I was at work which explains the lack of pics :Smile:
    - - - Updated - - -
    EDIT: Got another offer of £165, that gives me a little profit too. Again, highly recommended to get done.
     
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  17. exec Premium Member Club Supporter

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    ^ I wonder who buys them and what they do with it?

    How are you finding the car with the new cat compared to old OEM?
     
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  18. Chunkylover53 Expert Advisor ★ ★ ★ ★ ★

    No difference in noise, slightly less hesitation when accelerating though I also filled up with BP Ultimate which may have contributed towards that. I ended up selling the CAT for £180 to a metal recycling firm, I assume they will melt it down and extract all the precious rhodium, palladium and platinum.
     
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  19. exec Premium Member Club Supporter

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    Acceleration should defo improve a bit as aftermarket cats are less restrictive, probably bit of both as BP Ultimate makes the car a bit more responsive too.

    Hopefully your car is safe now and you've made a few bob too.
     
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