When did the Chevrolet Silverado started using AIR pumps and why?

[tonyghkbve]

I've seen some 1999-2000 Chevrolet Silverado equipped with AIR pump system. I wonder why were they installed and when did they stopped using them.

[MaverickZ71]

Depended on the model and the Federal smog requirements for that year. They started putting on AIR pumps even before catalytic converters, way back in the late 1960s or early 1970s. The idea was to inject additional oxygen into the exhaust stream to more thoroughly burn/dissipate the exhaust gases. Most AIR pumps were driven by a separate belt and it was all to easy to cut the belt to gain a couple of horses, but looking back, doing so just probably clogged up a restrictive cat that much sooner. I had a mid-70s Impala with a 350 that had an AIR pump, but my 79 Trans Am 400 does not. Go figure. The trucks may have come on-line with the additional smog equipment after the cars did, just like the CAFE fuel mileage requirements did not apply to trucks until more recently.

[newdude]

2001 appears to be the last year that I can tell. Same happened to EGR. 2002 was the last year for that. My guess, is via evolution of the LS engine family allowing it to burn and run much cleaner was the culprit for removal of alot of that stuff, especially with all the computer controlling that is on them now (drive by wire, advanced PCM, VVT, etc.) and therefore they were able to remove alot of that stuff. An example of computer controlling would be the 6.0 and 6.2 engines say, 2009 and newer. The engine changes timing on a cold start to heat the exhaust much faster for about a 50 second timeframe. Essentially causes combustion in the manifolds. Only thing GM trucks really have for engine emissions systems is PCV and EVAP.

[WilliamBos]

2001 appears to be the last year that I can tell. Same happened to EGR. 2002 was the last year for that. My guess, is via evolution of the LS engine family allowing it to burn and run much cleaner was the culprit for removal of alot of that stuff, especially with all the computer controlling that is on them now (drive by wire, advanced PCM, VVT, etc.) and therefore they were able to remove alot of that stuff. An example of computer controlling would be the 6.0 and 6.2 engines say, 2009 and newer. The engine changes timing on a cold start to heat the exhaust much faster for about a 50 second timeframe. Essentially causes combustion in the manifolds. Only thing GM trucks really have for engine emissions systems is PCV and EVAP.

 

Guessing the removal of EGR has contributed to longer OCI's and longer service life of 350,000 miles?

[Gurrzt]

I have an AIR pump on Sara (2001 Z/28).

 

She does not mind being pumped!