EGR Valve took a dump

I have the plate on the PDI manifold like the picture, but I also cut off the EGR port adapter that went into the manifold there and then bolted it back up to the manifold while leaving the plate installed. I then just used a little high temp RTV between the adaptor and the steel plate to seal things up. Unless one is really looking for something, it just looks like any other EGR equipped ISX out there with what looks like a spacer between the EGR adaptor and the manifold. Cummins never noticed it when I last had it in. One mechanic at my dealer that I trust did notice it and chuckled when he saw it. He has known for quite a while I have been tinkering with this engine regarding EGR issues. He is the one that I had plug up the engine and read the codes and told me the EGR had taken a dump and he agreed with me just let it sit and not waste the money on a replacement.

Not having that extension tube that goes into the intake out of there, frees up a lot of space in the manifold for air flow. Better performance, quicker response, better mpg, and must be getting a better burn because my oil samples show improvement as well.

 

Really does make one wonder how the ISX is getting any air at all into the cylinders with the design of the stock intake. That EGR tube takes up the lion's share of space in there. On the surface, putting on the PDI intake made sense, and in reality, it did make a difference. A person just needs to take that ISX intake and EGR tube apart to get a perspective if they haven't before and the questions on how the engine is getting any fresh air at all will pop up in their head!

 

I didn't change the exhaust off the turbo, but I did install a turbo blanket on the turbo. I believe it helped a little as well in keeping the exhaust flowing better. EGT temps dropped, on average, about 75-100F. I got a turbo blanket off of EBAY for around $100. Quick install in about a minute. It has been on there for about 60,000 miles. "Opened up" the exhaust when I bought the truck by removing the under cab muffler and putting on a resonator.