Things to do or not before smog test?

Discussion in '80-Series Tech' started by e9999, Jul 17, 2005.

  1. e9999

    e9999 You want to do what...? Moderator

    Messages:
    16,655
    Likes Received:
    530
    Joined:
    Sep 21, 2003
    Location:
    US
    OK, here comes another required CA smog test.
    Passed just fine a bit over a year ago, but I'd rather not have to deal with problems and have to go back... Plus this may give me the necessary motivation / excuse to do something worth doing on the truck...

    Anything I should or should not do before taking the test?

    I have replaced the plugs recently, the plug wires test fine, and I will probably put in a new rotor and cap by then. Also replaced PCV and air filter.

    I was thinking of running a couple of Techron injector cleaner bottles in the gas for a few weeks taking the test. That should not hurt.

    I have also been thinking for a while about doing the "Suck Seafoam in the intake" trick but I'm wondering if that's a good idea to do it now given that that would likely dissolve and make a bunch of gunk flow around. Waddaya think? OTOH, it might clean things up a tad.

    Taking the intake off and cleaning the inside seems way overkill, no?

    (Only 78k or so)
     
  2. offroadkid

    offroadkid

    Messages:
    979
    Albums:
    1
    Likes Received:
    42
    Joined:
    Oct 22, 2003
    Location:
    El Dorado Hills, Ca.
  3. e9999

    e9999 You want to do what...? Moderator

    Messages:
    16,655
    Likes Received:
    530
    Joined:
    Sep 21, 2003
    Location:
    US
    I'm surprised. Not sure how the oil cleanliness would be reflected in what is reinjected by the PCV... Maybe more fumes?


    I do remember reading here that somebody noticed a temporary improvement in smoothness with cleaner in the gas... maybe not a bad thing if there is some left in the gas during the test?
     
  4. Lars

    Lars

    Messages:
    658
    Likes Received:
    1
    Joined:
    Apr 17, 2003
    I've always heard new oil and clean air filter helps.
     
  5. Hants

    Hants

    Messages:
    439
    Likes Received:
    0
    Joined:
    Feb 16, 2004
    Location:
    Behind the bar
    Replace the gas cap. Mine passed inspection, but the tech cleaned/wiped/inspected it for a long time (many 10's of seconds) before he put it on the machine.

    Several weeks later I discovered it was leaking fuel -- now I wonder how it passed the pressure test at all.

    Also, I've heard that if you've recently had the CEL light reset (fixed the underlying problem or not) or disconnected the battery, they can/will fail you for insufficient data.

    I'd be leery of additives or wild-n-crazy cleaning exercizes within a tank or two of testing.

    May you pass the first time! :beer:
     
  6. Gumby

    Gumby Supamod Staff Member s-Moderator

    Messages:
    12,220
    Likes Received:
    668
    Joined:
    Dec 13, 2002
    Location:
    Knee deep in hookers and gin
    If you have an OBDII truck (96+) you will need to have all of your monitors enabled to pass. You can't just reset your light.

    I fast idle mine while waiting in line. I see people fail because the cats get cold while they are waiting. I run 1500+ RPM to get it nice and hot.
     
  7. e9999

    e9999 You want to do what...? Moderator

    Messages:
    16,655
    Likes Received:
    530
    Joined:
    Sep 21, 2003
    Location:
    US

    so clearing up all the codes even if no CEL is not a good idea then -assuming I could even do that-?


    any point in putting premium in for the test?
     
  8. Brentbba

    Brentbba Former Golfer SILVER Star

    Messages:
    10,263
    Likes Received:
    999
    Joined:
    Mar 27, 2003
    Location:
    OC, CA
    Just go and don't worry about it. hehehe :flipoff2:
     
  9. elmariachi

    elmariachi

    Messages:
    1,977
    Likes Received:
    23
    Joined:
    Jan 4, 2005
    Location:
    Shufflin' Through the Texas Sand
    In Texas, the inspection station computer can tell if you reset the codes in the last 300 miles. Likely the same in other states, considering that everything we have here our legislators learned or stole elsewhere.
     
  10. NorCalDoug

    NorCalDoug problems solved daily...

    Messages:
    6,293
    Likes Received:
    118
    Joined:
    Oct 27, 2003
    Location:
    uhhhh...duh...Northern CA
    Ditto.

    :D

    I've never had a problem with any of my 80s passing smog. The one I sold 4 years ago (1994 model year) passed with flying colors -- I had done nothing to it aside from a tune up a couple months prior to selling it.

    My assumption going into these tests is that if the rig is running well, I won't have a problem. If it's running rough, fix the problem before taking it in. Maybe I'm just spoiled with Toyotas (and hondas).
     
  11. Darwood

    Darwood

    Messages:
    1,957
    Likes Received:
    9
    Joined:
    Oct 8, 2003
    Location:
    Z.O.W.I.E. Headquarters
    I'm not sure if OBD-II even holds that detailed of information. I'm about ready to call BS on this but I need to do some research first. ;)

    Of course you all realize this just gives the pre-95 guys more room to talk.
     
  12. RavenTai

    RavenTai

    Messages:
    6,048
    Likes Received:
    46
    Joined:
    Nov 16, 2003
    Location:
    Dixie co. Florida

    Not in GA on a friends late 90's Chevy blazer, it that case you can clear the codes with a scanner in the parking lot 50’ away and as long as it does not set the code again it will not fail, but if you clear the codes by disconnecting the battery then it will have to go through a "drive cycle" (whatever that is for that vehicle) before it will pass. for Chevy I think a drive cycle was one warm up & one cool down. nto sure waht it is for an 80.

    No tail pipe sniffing in GA for 96 on, making the post 96 superior here.
     
  13. Darwood

    Darwood

    Messages:
    1,957
    Likes Received:
    9
    Joined:
    Oct 8, 2003
    Location:
    Z.O.W.I.E. Headquarters

    As far as I could tell by my research, OBD-II only sets "readiness flags" after a certain drive cycle which tend to involve 30 mph driving and 55 mph driving. Other than that, it seems OBD-II doesn't seem to store information other than thrown codes.
     
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.