Gaming my SAI to the ECU.
 

My secondary air pump fails regularly, every couple of years. At first, I got replacements from the junkyard, those went somewhat quickly. This last time I got a Chinese version for I think about a hundred bucks vs VAG's $400. It's so aggravating that this thing that runs for a couple of minutes then shuts off should toss off a CEL which I have to stare at while I procrastinate on yet another pump. Interestingly, the affected car is my 62k 04 1.8T Passat. My 03 A4 which I've had for 7 years has never had a problem.

To wit, I'm wondering if I can fake out the computer to think everything is ok with the SAI. The code says "low flow." Is there actually a measurement device on the pump, and if so, could I rig up a voltage source that would simulate the sensor's output?
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Assuming the pump runs and blows air, there is usually an air flow one way check valve within the SAI system. That could be causing flow issues or can sometimes leak and allow moisture from the exhaust to back flow and build up in the SAI pump causing premature failures.