London Low Emission Zone - Feasiblility Study

I’ve got a 99.5 VW tdi with the quintessential diesel intake clogging problem. By removing the EGR, I can fix this problem, and the egr on a diesel doesn’t affect ignition timing like it would on a gasonline engine. In fact, it is reported to have more power (but less fuel economy) because of increased oxygen introduced into the cylinder. Removing the EGR also reduces the particulate matter emissions. But it also increases the amount of NOx emissions, which I feel is at least as damaging as PM emissions. In trying to choose the lesser of two evils, I am looking for hard data that shows how much of an increase in NOx emissions I’ll have by removing the EGR as well as how much of a decrease in fuel economy and PM emissions I’ll experience. Anyone got any info or data source links? The tech forums don’t get into emissions, just the ABC’s of doing it.

Typically you will set off the check engine light when you mess with the EGR system (the flow is usually monitored). That’s fine if you don’t have inspections, but I am guessing you do. I’m not sure about the VW system, but typically the passageway to the EGR gets plugged up and changing the EGR valve does nothing to fix the problem. There are flexible drill bits available now to clean out the EGR passageways to correct the plugging problem (or at least fix it for another 80K miles).
The NOX would go up as well as the combustion temperatures, at least on a gasoline engine.
I don’t believe there will be any negative effect on mileage with the removal of the EGR, unless you had unburned fuel in the exhaust - which would be another problem.