whats the point of the air pump?
Thread Starter
Staging Lane
Joined: Nov 2006
Posts: 66
Likes: 0
From: oklahoma
whats the point of the air pump? i have read several threads, i have a 94 z28 and i hate the air pump, its in the way alot of the time, some say i can take it out no problem and some say it will throw codes, whats it for anyway?
correction guys, the air pump pumps extra air into the exhaust so the cat can burn hydrocarbons better. It doesn't heat up the cat cuz it just pumps air from the intake into the exhaust.
catalytic converters require oxygen to operate.
however, if the engine is running ideally, it has consumed all of the oxygen already.
this of course, can be a slight problem.
when in closed loop operation, they get around this by "bouncing" between slightly rich and slightly lean... the switching O2 sensors you're used to seeing.... in this way, the cats get enough oxygen to operate.
but during open loop operation, the cats may or may not be getting enough oxygen... so under specific conditions, the PCM kicks on the air pump, blowing fresh, O2 rich air into the exhaust.
btw, in case you're wondering... at wide open throttle, there was no EPA emissions requirement, so even though its kicked out of closed loop, and probably running on the rich side, the air pump is not kicked on.
however, if the engine is running ideally, it has consumed all of the oxygen already.
this of course, can be a slight problem.
when in closed loop operation, they get around this by "bouncing" between slightly rich and slightly lean... the switching O2 sensors you're used to seeing.... in this way, the cats get enough oxygen to operate.
but during open loop operation, the cats may or may not be getting enough oxygen... so under specific conditions, the PCM kicks on the air pump, blowing fresh, O2 rich air into the exhaust.
btw, in case you're wondering... at wide open throttle, there was no EPA emissions requirement, so even though its kicked out of closed loop, and probably running on the rich side, the air pump is not kicked on.
