high mileage ISX.

They moved the EGR to the cold side starting with the '07 engines.

 

Took out the adaptor that connects up to the intake manifold. Chopped off the extension that goes into the manifold throat. then put a 1/4" steel plate between the adaptor and the manifold. Bolted it all back up. The original O ring seals up the steel plate to the manifold. Used high temp RTV on the area between the adaptor and the steel plate. Mod took me about an hour to do and I let the RTV set up for 24 hrs before running engine.

EGR is still plugged in, but after over a couple of hundred thousand miles, it finally took a dump like most do over time. But, I am not going to change it since no EGR was getting to the intake anyway. Except for the fault code that shows the EGR valve took a dump, did not notice any change in performance. My tech I use to diagnose my engine just chuckled when he told me the EGR took a dump. He has known for quite a while how I modified things and knew when he told me that I would not change the darn thing out.

Gained almost 1 mpg average out of the mod, with an average mpg of mid 7's year round (calculated pump to pump... not off the display which shows consistently 8mpg or better). My oil samples look way better after the mod with the latest one showing 8ppm iron and 1ppm lead after 25,000 miles on a 625,000 mile engine. Soot was around .1 in that time also.

Was worth doing it in my book.