."I'd like to know how the EPA found out about this hack "
Good question. I can understand how an individual could, for example "how c ome my car runs like shit right after testing" and this happening to everyo ne who owns that model. Then it gets around on the internet, the rest is hi story. Reverse engineering by watchdogs, or possibly reverse engineering ef forts by a rival car company.
But there is another issue. You know EGR does not turn a sportscar into a P into necessarily. Long time ago we used to plug up the PCV on cars because "It is losing vacuum with that thing". Yeah, not enough to even notice, and plus PCV makes your oil last longer. It also eliminates the crankcase smel l.
The EGR system actually makes cheap gas burn better. The system basically r educes the O2 content of the mixture which slows down the burning. this is what the additives in premium gas do. This allows for higher compression ra tios and more advanced ignition timing.
With premium (higher octane) gasoline you actually get a little bit more po wer. In the old days we could set up our cars for premium, and you tell you r olady "Don't put regular in my car !". Now the engine is tuned to the gas dynamically. The ECM literally advances the timing until the knock sensor reports a knock, and it is right there, you never hear it. With cheaper gas it will retard the timing.
If you disconnect the EGR in an engine on a modern ECM it will sense a knoc k and retard the timing to the point where you are not getting much of a bo st - if any. However on the manufacturing level you can change the program in the ECM to tolerate more knock, especially at 2,500 RPMs and heavy load full throttle. If that is the engine condition right now, WolksVagon can be pretty sure the driver it not going to object to a little ignition "ping".
The old days were great. We went to the car lot, said "Gimme the keys to th at Olds over there" and they did not aask for a license or anything, you to ok it for a ride with the dealer plate and put it on the freeway and see ho w passing gear works, see i it peels rubber, see if it overheats. Then you find out whether it has brakes or not.
Now, you get a carfax on it, look up the previous owner on the county regis ter to see how many times they have been sued or arrested, have someone run the codes to make sure it hasn't been reset. Use a DOT approved tread dept h gauge... Sickening.
They used to sell cars touting their performance, now they tout the interne t access and cupholders. and some of them run Windows with the touch screen . Look Man, I want a spedometer, oil pressure, engine temperature and amps or voltage gauges. Matter of fact, keep your damn radio, I'll go to Crutchf ield. Fuck all that.
But you simply cannot buy that, you have to buy what they got.
Caveat emptor.