Change pcm vin on obd2

[GaryDoug]

IMO, the 1990 Clean Air Act Amendments had a lot to do with it. Before that, anyone with $10 could easily defeat the pollution control features in their car by just replacing a socketed chip. The Act eventually required, by 1995, the extension of equipment guarantees to as long as 8 years for components supporting the EPA requirements. Manufacturers had to do something to keep the owners from modifying their cars in ways that caused early failures of these parts. At the same time, the OBD-2 system was mandated, and I suppose it was convenient, expedient, and cost-effective to further restrict the capability of changing the computer system to authorized personnel only. Personally I do not think this is a bad thing; I like breathing clean air.