Rejected on smog test

Tiny
WXGESSER
  • MEMBER
  • 1996 NISSAN HARDBODY
  • 4 CYL
  • 2WD
  • MANUAL
  • 165,000 MILES
Four parameters "not completed" on (more than one)smog test. First one @ 163,359 mi. Most recent @ 164,898. Dealer says new ECM is needed. No CEL on. Fuses all ok. New battery installed 12/2010. Veh runs fine usually. Sometimes (starting very recently) it idles and runs rough, as though it is running out of gas. Last smog tech said the times he has seen "rejected" were when battery was failing or otherwise not strong enough.
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Saturday, June 4th, 2011 AT 10:05 PM

5 Replies

Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
What were the parameters not completed resulting in the smog test failure?
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Sunday, June 5th, 2011 AT 4:17 PM
Tiny
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OBD catalyst, OBD evap, OXY sensor, and OBD exhaust gas. Smog tech said, in his experience, rejected vehicles usually don't actually have anything wrong mechanically.
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Sunday, June 5th, 2011 AT 5:35 PM
Tiny
KHLOW2008
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Yup, the computer needs to relearn and some driving is required to get them working corrrectly.

Try driving on the highway for 20 minutes, get to city driving for another few minutes and back to the highway again. Recheck the parameters.
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Sunday, June 5th, 2011 AT 9:06 PM
Tiny
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First reject smog test 4/11 (BEFORE my plates expired) @ 163,359 mi. Tech said to drive it around a lot. Second reject test 4/30 (plates now expired) @ 163,906 mi. I found a drive cycle and completed it the best I could, after which I went directly to the smog station (5/4 @ 164,058 mi). Result: reject. Fourth reject test 5/16 @ 164,421 mi. (I'm not a glutton for punishment. I have to get a new smog test each time before I can get a new 10-day movement permit, and they limit the total number of permits you can get.) Fifth reject 6/3 @ 164,898 mi. This computer sure is a slow learner.
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Monday, June 6th, 2011 AT 9:42 AM
Tiny
KHLOW2008
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Reset the computer and perform the drive cycle again.

Constant driving sometimes do not work and the procedure that I mentioned had been known to work for others.
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Monday, June 6th, 2011 AT 12:33 PM

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