Install was very simple, also installed the FRX at the same time noise reduction was not noticeable but idle was smoother and throttle response was improved.

After 200,000 miles of driving my truck I decided to make some mods to my truck. The Riffraff HPx is one of the best things I've ever done to my truck! I did it along with the Riffraff FRx. My truck is incredibly smoother now.

smoothed out idle and seems to start easier

I installed both the HPX and the FRx and I've noticed a better throttle response, smoother idle, and overall better performance of my 7.3L.

Install went smooth, had to tighten up quite a bit for it to seal up well. One word of advice is take the air intake tube for MUCH Better access to driver side plug. Noticed a good noise reduction in idle when the truck is warmed up, Overall real happy with this mod.

Good product for the money, however I noticed zero difference in idle or engine noise after installing the high pressure crossover. Installation was very easy. But it takes time for the air to get out of the system.

I've bought the hpx line for both my trucks and a few other things, every thing they sell is top notch. Always a happy customer here.