Dredging up my 2 year old thread.
Just passed another smog test, with mostly better numbers than 2 years ago. whohoo!
The difference between this test and the previous one was:
Got rid of the Bosch 02 sensor, replaced with NTK about 22 months ago.
Newish 30x9.5x15 tires vs LT235/75/15 tires previous. Check slight rpm difference.
Nothing else.
A few months back I ran some Gumout regane through the tank, and occasionally I have tried some MMO in the fuel tank at about 3 to 4 oz per 10 gallons. Mostly in a bid for better numbers on this Smog Test. There were no additives in the fuel during this latest test.
I cannot find my reports from '07 or '09. here are '05, '11, and '13.
The Spark plugs are from 2005, only have about 30k miles on them. Not the plugs I would buy today for it, but they are the Bosch platinum +2. I have not pulled them since 05. Kind of worried they might be seized in the heads.
These tests were all performed at different smog stations. Don't know if that make comparisons invalid or just less accurate or not a factor.