Implementing EGR and its Effect on Fueling

Does anyone have any experience on whether EGR implementation has an effect on required fueling? I know on turbocharged vehicles a cooled EGR system can be used in place of extra fueling on boost for temperature control, can this same theory be applied to N/A engines?

Also, besides lambda, EGT readings and knock detection, are there other methods to determine if the engine is running too lean?

Thanks

To date I've had very little personal experience with EGR so it's difficult to add much value to the conversation. Many modern engines now make use of hot internal EGR by using the cam phasing to control overlap during certain areas of the engine's operation. Cooled external EGR can seemingly offer improved fuel economy as a result of the cooler EGR though.

There is an interesting thread on NASIOC forum about the FA20DIT engine technology employed in the current generation WRX. The thread details many other technologies on this engine but also discusses the implementation of both internal hot EGR as well as the high pressure cooled external EGR systems. If you have a spare hour, it makes for interesting reading. Link is here: http://forums.nasioc.com/forums/showthread.php?t=2687550

Thanks Andre, I'll give it a read.