Quote:
Originally Posted by elp_jc
For those out of warranty, how much that pump really affects emissions? If it was to be eliminated, would you get a CEL? Cats might take a minute or two more to heat up, as they also have heated sensors, and no other car has that crap that I'm aware of.
Anyway, has anybody figured out what the hell causes the engine to load dramatically after about 4 minutes of starting? You can hear that loading by a dramatic change in exhaust noise. Does it have anything to do with that spupid valve? The 240 seconds it takes to do that sounds too much like coincidence, no?
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It really does effect emissions when the cats are cold. They really don't work their magic until they are hot. Most cars have the cat heat up cycle built in, you just don't hear it as much as you do on the M3.
If the secondary air pump was pulled out, you would lose emissions readiness and a CEL will be thrown. It's part of the biggest problem with the E39 M5. The secondary air passages in the head become clogged and then the car sets a slow flow code on the secondary air pump. Then the car will not pass emissions without software to disable the secondary air system.
For your reference:
http://www.sae.org/events/training/s...5baltusis3.pdf