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96 850 T Fails E Test twice... HELP! 850

posted by  jaker on  Tue Sep 8 13:32 CST 2015
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last visit: Thu Oct 23 15:22 CST 2014
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My 96 850 T has high readings of HC and CO when tested ... so it fails the E-test we have here.
The mechanic indicated that he thought the engine was running rich and as I have been meaning to do the PVC cleanup overhaul I started there. I thought it was possible that I might have a vacuum leak or something that was not allowing crank case gases to be properly burned.. hence the higher readings.
Without doing the whole job I started by cleaning the MAF and after considerable aggravation was able to get to the PTC "valve" and clean the nipples. There were a few suspect hose issues that I fixed while in there. Finished last Friday and could not do retest until today and found that my average fuel usage over the weekend fell from 10.1 liters/100 kms to 9.2 L/100kms. That's about a quarter gallon of gas every 60 miles. So that was great and I thought that just maybe that was it. NOT SO. Retested today and HC and CO came down a bit but not enough to pass. I am getting no DTCs ... I stupidly cleared them a couple weeks ago (without writing them down) and nothing is showing yet. I am failing at both idle and 2500 RPM.
Todays readings - (2500 RPM) HC- 203 ppm - CO 3.85%
- ( At Idle) - HC 430 ppm CO - 7.85 %
Live Data readings today have not changed anywhere significantly since before the work. If there is some reading there that may be an indicator let me know.
I do get a I/M Readiness reading and both the CAT and EVA icons are Bold and Circled... seemingly indicating a trouble spot.
I have no idea when the Catalytic converter was last replaced ... would a malfunctioning CAT Converter create those kinds of high pollutant readings? As you all know... they are very expensive... so would want to be fairly sure at least.
Anyone out there who has any ideas or experience with this, your insights would be welcomed.
Where to start as priorities and cost? Thanks.








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    96 850 T Fails E Test twice... HELP! 850

    posted by  KlausC on  Mon Sep 14 20:54 CST 2015
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    last visit: Fri Oct 24 10:15 CST 2014
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    While the PCV and PTC nipple are important and need to be cleaned out, if you have already determined that the vacuum lines are all intact and the elbows are not leaking air, check the exhaust for leaks before the front O2 sensor. A leak in the down pipe, a leak just in front of the cat and sometimes a minor leak at the rear O2 sensor can cause bad readings and make the engine run rich.

    Check all of the intercooler pipe fittings and make sure they are snug all of the way to the throttle body. How about the air pipe from the air cleaner to the turbo, any cracks?

    --
    My back feels better when I sit in a Volvo seat








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      96 850 T Fails E Test twice... HELP! 850 1996

      posted by  jaker on  Tue Sep 22 14:52 CST 2015
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      last visit: Thu Oct 23 15:22 CST 2014
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      Thanks for your insights Klaus.
      Was away all last week with a canoe rather than a car. Nothing EVER goes wrong with that.
      I believe that I have the vacuum lines and pipe fittings covered but will get her up in a hoist tomorrow and check around the exhaust... will let everyone know if there is any revelation. Thanks again.







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        96 850 T Fails E Test twice... HELP! 850 1996

        posted by  KlausC on  Tue Sep 22 18:47 CST 2015
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        last visit: Fri Oct 24 10:15 CST 2014
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        Check the flex portion of the exhaust and both ends of the cat for obvious air leaks.
        --
        My back feels better when I sit in a Volvo seat








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          96 850 T Fails E Test twice... HELP! 850 1996

          posted by  jaker on  Mon Sep 28 15:01 CST 2015
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          last visit: Thu Oct 23 15:22 CST 2014
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          Thanks Klaus,
          Got my 850T up in a hoist today and there was a crack almost all the way around the pipe at the downwind end of the Cat. Lots of gases escaping. Welded a new piece of pipe in there.
          Will see if that makes significant changes in E test readings and will let you all know.
          Thanks again.








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    96 850 T Fails E Test twice... HELP! 850

    posted by  Herb Goltz on  Thu Sep 10 08:59 CST 2015
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    last visit: Fri Oct 24 13:23 CST 2014
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    It looks like you have unburned fuel (high hydrocarbons and carbon monoxide), so you are running rich. In the instances where I have needed a cat I have had high NOx (but it doesn't look like NOx was measured in your tests).

    Start with the basics-- when was the last time you replaced plugs, wires, cap and rotor? Get some data on your front and rear O2 sensors when the car is warmed up.

    I am wondering if you have a big leak in your evaporative emissions system. Drive it enough to get the codes to reset (check for pending codes now and post them here).

    Good luck!








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      96 850 T Fails E Test twice... HELP! 850

      posted by  jaker on  Thu Sep 10 14:55 CST 2015
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      last visit: Thu Oct 23 15:22 CST 2014
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      Plugs, wires cap and rotor were replaced last December. Upstream O2 sensor was replaced last October.
      I know that I am due for a PCV system overhaul.
      Anyway... my regular mechanic (who is not affiliated with this government program and hence cannot do the work, says that I just have to bite the bullet, get a complete checkover to the tune of about 175.00 from the government accredited shop, spend a minimum of another 250.00 towards fixing whatever shows up and then get a partial "pass" which is good for 2 years.
      They get you coming, they get you going.

      And don't get me wrong... I want to find out what's wrong and fix it... but this way my choice of mechanic, parts and source are all mandated by someone I don't know... can't say I like that at all.

      Anyway... thanks for your comments.








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        96 850 T Fails E Test twice... HELP! 850

        posted by  Herb Goltz on  Thu Sep 10 21:28 CST 2015
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        last visit: Fri Oct 24 13:23 CST 2014
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        I see now that you are in Ontario too-- I'm in Aurora. I just went through the conditional pass on my wife's car (a Toyota, not a Volvo). It's a bit of a racket-- cost me $212 to get a pass on a car with a bad cat-- started with an e-test that I knew it would fail (a persistent P0420 and a rear 02 sensor with wide range swings), then $145 for diagnostics (mostly the old dyno e-test and a few follow up measurements at Canadian Tire), then a retest. No improvement in emissions, but the bad cat would have put it over the $450 you need to spend to get the conditional pass. No improvement for the environment, just a cash grab.

        I think your best bet is still waiting for codes to see if they point to the reason for the rich running, fix them and go for a retest when the monitors are ready. Failing that, I would get the diagnostics done somewhere reputable, then have the fixes done somewhere affordable-- you can take your time after you get your stickers.

        Good luck!








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    96 850 T Fails E Test twice... HELP! 850

    posted by  james_a_sousa on  Wed Sep 9 18:13 CST 2015
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    last visit: Thu Oct 23 18:51 CST 2014
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    Wouldn't it be cheaper and easier to have a Volvo tech troubleshoot it or do a tune-up?

    I think that here in Massachusetts, you can present a receipt for a tune-up and get a pass.







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