Air Pump On A 90 Mercedes 300E 2.6L

I have a 90 300E 2.6L that runs great with 245,000 miles on it. Recently I switch mechanics and it was brought to my attention that my car does not have an air pump.
Can someone explain to me what is the purpose of the air pump and if it is needed for the car to perform properly?
Thanks.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

an air pump. Can someone explain to me what is the purpose of the air pump <<
The air pump is activated by the computer for a minute or two on cold startup to blow air into the exhaust ahead of the oxygen sensor to trick it into sending a lean signal to the computer to cause it to enrich the mixture for warmup. Like a choke function. Then it turns off.
Bill Ditmire Ditmire Motorworks,Inc. 425 White Horse Pike Absecon,NJ 08201 http://www.ditmire.com 609-641-3392
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Bill Ditmire wrote:

I thought the purpose was to provide enough air so unburnt fuel would burn, thus heating up the cats faster.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Partly.. The Air Pump is used to add air at the exhaust ports to aid the in the oxidation of CO and HC to meet emissions and also heat the cat. It has nothng to do with tricking 02 sensor . The ECU will not let the pump circuit come on unless it is in open loop. Once the system goes into 02 sensor closed loop, the pump circuit is done..
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Damn! $1200 for an air pump? $441 is the lowest price I have seen for quick search at Mr. Auto Parts.
Air pump is used only when engine is cold to supply extra air while idling. It is part of emission control... but rarely used device... only when engine is cold first thing in the morning.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Emissions reduction, it injects air into the exhaust so the catalysts can reduce the hydrocarbons.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.