O2's and Air pump...
 

Does the computer compensate for when the air pump is pumping in air into the exhaust? I'm curious for I noticed that the air pump pumps it's air in before the O2's and I'm wondering if it messes with the O2's.

Thanks!

Ted

Air pumps in air to help heat up the Cats, The Air pump runs for about 30 seconds, your O2 sensors are in open loop until you reach a certain ECT. Therefore the O2's will ignore the air pump.

However, I'm not sure if the air pump comes on if you start the car once already warmed up, as you would be in closed loop by then.

I removed my pump long agin, I know it comes on when cold, not sure about hot starts.

So the air pump is used to heat up the cats, hmm, so it's just for helping out on the start up's then huh? Does anybody know if it runs any other time for if that is the case then a person should be able to pass a sniff test after the car has been warmed up, right?

Certainly only runs on start ups.
By the time I get to my end of the road it would be off by then. So it would have no effect on the sniffer test. Its just to help the cats to become effective quicker, once they are up to temperature the O2's will help with fueling to keep it around 14.6 where th cats work best.