This product Quieted down my engine and improved my cold starts. However i had some trouble with the orings breaking due to myself not tightening the fitting all the way in. Make sure before you install you put some lube on those orings and drive the fitting slowly making sure you do not catch the oring on the edges and tighten until fully seated. Then install the line nut one by one making sure not to cross thread it. This product is worth the money.

This upgrade dropped right in. I didnt have to remove anything from the truck to install and it only took about 10 minutes.

Perfect fit. Well made. No leaks. Quiet down engine a little or aleast it idles smoother. Looking forward to get fuel crossover as well.

I purchased a 97 7.3 last two years ago for cheap and have done some minor repairs since including new injectors. With 290,000 miles on the truck it was obviously time. After replacing the injectors i still had a moderate 'cackle' at idle and rough idling, after thinking really hard and some extensive research and reading mixed reviews i decided to give the HPX a try, needless to say the results blew me out of the water and my rough idling and cackling has dissappeared, I also noticed better throttle response and slightly easier shifting. Great prouduct for the money and would recommend to everyone, riff raff has never let me down.

Easy to install, and noticeable difference in the sound of the truck before and after. Very happy with this product

Installed in minutes, perfect fit, and it really quieted down the engine at idle and working! Would definitely recommend this product to everyone!

Perfect fit, smoother idle, 2 decibels quieter. I would buy not for performance but longevity on your motor

Quality materials to build a quality product.

Fast shipment easy install performance as promised will be ordering more items from riffraff. Highly recommend product and vendor