Is the smog pump required by emissions??

Pokageek

Active Member
Jun 10, 2005
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MA, USA
Hi everyone. Anybody know the answer to this one? Reason I ask is that I understand that the smog pump is only used during the first 10-20 seconds of start-up. They don't check for this equipment under my hood and they put the car on a treadmill and measure the stuff coming out of the tailpipe but all after the car is running. So who needs it? Just states like California where it is more strict??

And how about the egr? Will the lack of one cause you to fail the tailpipe test?
 
egr introduces inert exhaust gas into your combustion chamber. this gas reduces combustion tempurature thus reducing NOx, or oxides of nitrogen, that cause photochemical smog(that brownish yellowish hazy stuff that hangs in the air on a hot day). But it depends on what state you live in.
 
The smog pump is used at all times, sans WOT. During start up, the flow is kept upstream. Once the motor is warm, then it diverts to the cats. It does provide the 'fuel' to help further catalyzation. It should help on the treadmill.

As said, the EGR helps. The only reason to remove it is aesthetics IMHO (it is not used at idle or WOT). Lack of EGR w/o turning off the EGR function in the puter could cause leanness at part throttle, which can adversely affect emissions.

Good luck.
 
skylovia said:
egr introduces inert exhaust gas into your combustion chamber. this gas reduces combustion tempurature thus reducing NOx, or oxides of nitrogen, that cause photochemical smog(that brownish yellowish hazy stuff that hangs in the air on a hot day). But it depends on what state you live in.
:stupid: