Written by Joel Paynton
Some time ago, there was a love-hate relationship with the Clean Air Act and many mechanics and owners who tended to view diesel engine emissions controls as evil. That was because most carburetors and vacuum control systems were not terribly reliable: as a result, fuel economy and survivability suffered. Entering the 80’s and the era of fuel injection, emissions systems suddenly became more reliable and usually improved the overall performance of an engine; at the very least, they did not hinder it. Computer controls allowed for much more precise engine operation. Despite this, diesel engine emissions controls sometimes still have that original stigma attached to them. In the early years, people often solved their drivability problems by removing all the emissions controls, retuning the engine’s performance – and pollution output – to pre-emission levels. This was illegal then, of course, and remains illegal today even though some people still remove EGR valves and catalytic converters.