Cats can only live a long life in kinda narrow circumstances. They are a lot of the reason EFI became pretty much universal. And FWIW, some manufacturers introduced OBD II in Kalifornia in 1994. Subaru was one, the 94 1/2 Calis could be OBD II.
Cats can only live a long life in kinda narrow circumstances. They are a lot of the reason EFI became pretty much universal. And FWIW, some manufacturers introduced OBD II in Kalifornia in 1994. Subaru was one, the 94 1/2 Calis could be OBD II.
FWIW my '95 Impreza was OBDII
Wow, we go from a weather complaint, to global warming, a brief stop on God Complex, and moved into gasious emissions.
This thread needs to be nominated for a snake award or maybe a geometrical one with the tangets....
Couple of things to clear up:
Cats are certified by proving their ability- and there's a procedure for that with the EPA and California ARB. It's pretty straight forward, and their requirements are WAY easier than OEM's requirements of proof.
Cats do die from temperature, but in terms of how the discussion here is flowing, the cause of that temp tends to more be crappy combustion and air fuel prep. They will run all day at 12:1, just as they do at 14.6:1 as long as the engine combusts the fuel well. If it starts misfiring, that's the beginning of game over. Where carbs have problems- with fewer control points, the range of a/f available are far more likely to result in fueled misfires- and those are what spikes the catalyst temp. Which either forces the system to sinter some (making the metal flow together instead of stay spread out), or worse- is hot enough to melt the ceramic structure.
Many, many rules changed in 1995 (California LEVII- what you think of as OBDII), and then later in 1999 (Federal Tier 2).
On a historical note- the change in emissions rules historically has been interesting. The first ones came out of bare need- people were having health problems due to air quality problems. A lot of that resulted in cars that had a tough time. Over time, the OEM learned a lot of new technology, and some of the rules were kind of updated to a later Tier 1 and LEVI. That happened in the early 90's.
So from 1968 to about 1990, there was one MAJOR step (the first one), and a handful of minor ones.
Since 1990, we've had one other major one in 1996 and 1999, and are now looking at a new major update in 2015 and 2018 (maybe on the latter). The change in technology to meet emissions standards in the time that I have been working has been really amazing. It was a HUGE deal in 1999 to make PZEV- all using really expensive catalysts. Now it's pretty common, to the point that we've done it on vehicles that you would never expect to be capable of doing it. OBD has gone from a system that barely was able to meet the law to one that we add new tests to help out find what is wrong. And the most obvious change- reliabilty- with the rules extending the emissions to 120k and 150k miles, powertrains are massively more reliable than they were in the past- even compared to 20 years ago. they have to be.
All of that was done under the blanket that the relative cost of cars has either not gone up, or has gone down. Amazing.
So, in two pages, I wonder what the next tangent will be.
looks like this is all it took to kill a perfectly good serpentine thread 
Tangents are fine. This is in the Off-Topic section. 
wbjones wrote: looks like this is all it took to kill a perfectly good serpentine thread
dang sorry about that
WooHoo! 78° on Thursday? Sweet! 
1988RedT2 wrote:
Franken-thread?
A little of this, a little of that, a dash of the other and you got yerself a pretty good stew. Just avoid celery salt; don't use that.
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