Page 1 of 2 1 2 LastLast
Results 1 to 10 of 11

Thread: Failed SMOG High NOX at 15mph

  1. #1
    Member
    Join Date:  Feb 2013

    Location:  San Diego, CA

    Posts:    39

    My VIN:    4626

    Failed SMOG High NOX at 15mph

    Hey everyone,

    I went to go get my DeLorean smogged last weekend and it failed the 15 mph NO test. It measured 1269 aand the max is 1148. In the 25mph test it measured 935 with a max of 978. The tech recommended that the O2 sensor be replaced but that was already done about 2 years ago. I took it for a good drive before the test to get it nice and warm. Any thoughs on what could be causing the issue or how to get it to pass. 2 years ago I had the engine tuned up at DMC california and haven't noticed any issues with it. Thanks in advance! 0011_001.jpg
    Attached Files

  2. #2
    Delorean Guru
    Join Date:  May 2011

    Location:  Northern NJ

    Posts:    6,498

    My VIN:    10757

    Club(s):   (DMA)

    Get a fresh tank of gas and run a can of Techron through the motor. If that doesn't work you may need to go back to DMCCA and get the car tuned up.
    David Teitelbaum

  3. #3
    Member
    Join Date:  Feb 2013

    Location:  San Diego, CA

    Posts:    39

    My VIN:    4626

    Quote Originally Posted by David T View Post
    Get a fresh tank of gas and run a can of Techron through the motor. If that doesn't work you may need to go back to DMCCA and get the car tuned up.
    Thanks David. Do you have a link for the Techron you recommend? Also, would running a higher octane just for the test help?

  4. #4
    Delorean Guru
    Join Date:  May 2011

    Location:  Northern NJ

    Posts:    6,498

    My VIN:    10757

    Club(s):   (DMA)

    Any large automotive supply should have Techron. Higher octane won't do anything but fresh gas (the right octane, regular) certainly will.
    David Teitelbaum

  5. #5
    Senior Member Ras12's Avatar
    Join Date:  Apr 2012

    Location:  New England

    Posts:    249

    My VIN:    10350 SEARCHING FOR VIN#16664

    Club(s):   (DMCNE)

    Swear by seafoam!!

    I never believed in additives and always thought they were gimmicks. Then I had a check engine light, it was running rich, and didn't pass inspection on my 2007 Yukon Denali. The sales person at O'Reily Auto encouraged me to try SEAFOAM in my gas, crankcase and more importantly trickle a full can down into the engine via the brake booster vacuum line. I did this and remarkably it ran 100% smoother and passed inspection with flying colors. I tried it on my Delorean with the same results. One word of caution, when you add the additive and drive the car you need to get on the highway or rev it up and you will create a smoke screen of white smoke. Check out some SEAFOAM videos on YouTube and you will see what o am talking about. Good luck!
    ---------------------------------
    SEARCHING FOR VIN #16664
    ---------------------------------

  6. #6
    Delorean Guru
    Join Date:  May 2011

    Location:  Northern NJ

    Posts:    6,498

    My VIN:    10757

    Club(s):   (DMA)

    A Delorean's fuel system is nothing like a 2007 Denali's. All you have to do is clean up the mechanical fuel injectors to get a better spray pattern. It also doesn't
    have to meet as stringent a standard as the 2007 does. Seafoam can also work but I don't have a lot of experience with it, I do with Techron.
    David Teitelbaum

  7. #7
    Senior Member Chris 16409's Avatar
    Join Date:  May 2011

    Location:  Fresno, CA.

    Posts:    1,154

    My VIN:    16409

    Does your car have an original exhaust system? The original cat is very good at scrubbing the exhaust gases. If you have a stage 1 exhaust, they are known to be not as efficient with NOx. I also get close to the limit on NOx with my Stage 1. If your original OEM cat has higher milage it may be time to replace that. Also check your CO mixture to see that you are in the proper range.
    Chris Miles

    For Better or Worse I own a DeLorean!
    1983 Grey Manual, VIN #16409, Fresno, California

  8. #8
    Senior Member NckT's Avatar
    Join Date:  Jun 2011

    Location:  Yorkshire UK

    Posts:    181

    My VIN:    No. 4068

    You could go back to basics, take your air filter out and see how dirty it is, and consider replacing it if it is dirty. New engine oil, check the spark plug gaps etc.

    Checking the switching of the o2 sensor would be a good, but the sensor just senses the oxygen content, not the burn quality of the fuel.

    If the re-test is free, as a quick fix you could drain off old fuel and make sure there's plenty in the tank of fresh petrol. Once you've got the pass you could re-use the old fuel in 1 to 5 ratio to use it up.

    Good luck
    Last edited by NckT; 06-01-2018 at 01:06 PM.
    RIP Rob van de Veer Top bloke

    I say Sir, I must be mad, one loves fixing K-Jet !

    Make sure there's plenty in the tank for the weekend chaps....

  9. #9
    Member
    Join Date:  Jul 2017

    Location:  Indianapolis, Indiana

    Posts:    80

    My VIN:    04629

    Might I suggest

    I use this fuel injection cleaner, it is specially formulated for our Bosch fuel systems. I swear my mpg is better after I have added this to my gasoline (x2 year)

    20180601_132104.jpg

    Yes, that's 04629 in the background almost ready for driving season!

  10. #10
    Member
    Join Date:  Jul 2017

    Location:  Indianapolis, Indiana

    Posts:    80

    My VIN:    04629

    Vin #'s very close

    Hey cdmcali

    Not to hijack this thread of yours, I just noticed your car and mine are only a few digits apart! Very cool since mine used to reside in Hawaii, until I moved back to the mainland.

    (Mine was originally sold by a Honda dealer near Long Beach)

Page 1 of 2 1 2 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •