1998 V70 Does the Air Pump Actually Do Anything?

[polskamafia mjl]

I think if myself as a clean-air enthusiast.

You're not alone, my friend.

[xHeart]

The discussion suggests air pump is necessary in snow country.
Which oxygen sensor determines air pump run or not run at cold start?

[jblackburn]

The discussion suggests air pump is necessary in snow country.
Which oxygen sensor determines air pump run or not run at cold start?

Front.

[cn90]

Hey jblackburn,

Learned something new.

1998 S70 GLT has air pump, but now has SAS delete mod using 90-cent Radio Shack diode.

I just got a 2005 XC90 2.5T, the newer model of 5-cylinder engines: no air pump as far as I can tell. Maybe I am wrong?

[jblackburn]

Hey jblackburn,

Learned something new.

1998 S70 GLT has air pump, but now has SAS delete mod using 90-cent Radio Shack diode.

I just got a 2005 XC90 2.5T, the newer model of 5-cylinder engines: no air pump as far as I can tell. Maybe I am wrong?

1999+ do not have an air pump.

The new engine management systems are able to adjust valve timing at startup to help warm up the catalyst more quickly, eliminating the need for both EGR and the SAS pump.

I don't know if that one has 2 catalysts or not, but that is even more common now - a small one right by the exhaust manifold to get it quickly warmed up, and then another downstream.

[erikv11]

Check this very thread, it is mentioned a few posts up: Air pumps were only installed by Volvo for a few years. Later years used timing to address some of the same emissions principles.

An air pump is not necessary in snow country.

[xHeart]

It tells me "need" is still there, only the "source/method" was changed... from SAS to VVT.

What source/method was used before the introduction of air pump (sas)?

[jblackburn]

It tells me "need" is still there, only the "source/method" was changed... from SAS to VVT.

What source/method was used before the introduction of air pump (sas)?

EGR.

Smog pumps were used back into the late 70's/80's as well.

[cn90]

jblackburn,

Thanks for info.
Over the years I hated that air pump business: spending too much time troubleshooting etc. etc., only to end up with the 90-cent diode lol...

[erikv11]

Ah, I see what you are asking xHeart. I meant that preheating the cat by smog pump or other means does not improve vehicle operation, so in that sense it is in no way "necessary" for cars in snow country. There is no "need" for it, the vehicle will run just fine with or without one, it doesn't matter.

A clear argument that there is no "need" for the air pump is that anecdotally, about half of the 96-98's came with an air pump and half didn't. That figure is based on the sample size of the four snow country vehicles that I have owned personally, but you get the idea.