im not saying that it has no positive effect, but overall, FOR THE DAILY DRIVER i would not cap the egr. If this is a winter vehicle or performance car then you may want to. the reason is that the vulcan pings enough as it is, and in the summer, this would not help the situation (or anytime for that matter) as is explained below:
Quote from another web site:
EGR has been successful in reducing NOx in gasoline engines. When an engine uses EGR, a percentage of the exhaust gases are drawn or forced back into the intake, at the direction of the engine's electronic control module (ECM), and mixed with the fresh air and fuel the engine is ingesting.
The purpose of using EGR is to lower the peak flame temperatures inside the combustion chamber. Forcing some exhaust back into the cylinder slightly reduces the concentration of oxygen and slows the burning a bit, making things a little cooler. EGR also absorbs heat, further cooling the process.
Now i know this information is not in debate, but i thaught it would illistrate in more detail, the purpose of egr.
mikehawk: i never said that spacers were a waste of money or even infered that they are. (personally i woud not invest in them). But that is totally personal opinion.