myf16
Well-Known Member
- Joined
- July 22, 2012
- Messages
- 155
- Reaction score
- 17
- City, State
- northern California
- Year, Model & Trim Level
- 96 Explorer XLT 4WD
This is the first in over 100 California smog tests that any of my vehicles has failed. It seems to me that a limit of 31 ppm for HC on a 1996 vehicle is too strict, but that's what it is these days. My 4.0L tested at 33 ppm. Other emissions were not close to their limits. HC was 20% under limit at 15 mph and 10% over at 25 mph.
I had driven normally 15 minutes before the test but parked for 10 minutes, which I know is not optimal. The gas tank was just filled with regular gas. I changed the air filter and spark plugs about 6000 miles ago. I changed an oxygen sensor at about the same time to eliminate a code. I changed the oil and filter about 2000 miles ago. The drivetrain has 135k miles on it. Original everything else.
For my retest I'm planning to:
- insist that the test occur immediately after hard driving
- remove the air filter before the test
- possibly change the spark plugs again
- probably use a different shop where they may have a steadier foot on the throttle
What do people here recommend for my retest? Also change the other 3 oxygen sensors? I bought a Bosch 15717 last time. I'd have to check whether the other 3 have the same length harness or if I need the longer 15719 for 2 of them. But that's a bit of work and about $90 (ebay prices).
Any other ideas, besides moving to a different state?
I had driven normally 15 minutes before the test but parked for 10 minutes, which I know is not optimal. The gas tank was just filled with regular gas. I changed the air filter and spark plugs about 6000 miles ago. I changed an oxygen sensor at about the same time to eliminate a code. I changed the oil and filter about 2000 miles ago. The drivetrain has 135k miles on it. Original everything else.
For my retest I'm planning to:
- insist that the test occur immediately after hard driving
- remove the air filter before the test
- possibly change the spark plugs again
- probably use a different shop where they may have a steadier foot on the throttle
What do people here recommend for my retest? Also change the other 3 oxygen sensors? I bought a Bosch 15717 last time. I'd have to check whether the other 3 have the same length harness or if I need the longer 15719 for 2 of them. But that's a bit of work and about $90 (ebay prices).
Any other ideas, besides moving to a different state?