SMOG FAIL ON NO

  • Tiny
  • Mkelee@cox.net
  • 1991 ISUZU TROOPER
  • 90,467 MILES

Would not pass smog I ended up replacing headgasket, valve job, valve lashcomplete tune up, all new vacuum lines and pcv, sensors ect. It still failed just barely, it failed NO
max is 704 @ 15 mph it measured 854
max is 606 @ 25 mph it measured 638
tech checked egr working fine
tech suggested changing timing from 13 degrees to 9 degrees
Any Ideas?

Do you
have the same problem?
Yes
No
Tuesday, February 21st, 2012 AT 12:47 AM

3 Replies

  • Tiny
  • Rasmataz
  • MEMBER

Check the EGR valve, a problem with it will caused the Nox -oxides of nitrogen to go high due to excessive combustion temperature

Was this
answer
helpful?
Yes
No
Tuesday, February 21st, 2012 AT 12:51 AM
  • Tiny
  • Mkelee@cox.net
  • MEMBER

The tech checked it out using a vacuum pump/gauge said it was working

Was this
answer
helpful?
Yes
No
Tuesday, February 21st, 2012 AT 1:15 AM
  • Tiny
  • Rasmataz
  • MEMBER

Tell him check the catalytic converter, oxygen and coolant temperature sensors-

Was this
answer
helpful?
Yes
No
Tuesday, February 21st, 2012 AT 1:29 AM

Please login or register to post a reply.

Other Smog Fail Questions