💪 FASS Fuel System Review: Is It Worth It for Your 6.7 Power Stroke?

If you own a Ford Super Duty equipped with the 6.7L Power Stroke diesel engine, you’ve probably heard the buzz around FASS (Fuel Air Separation System). But is this upgrade worth the money, or just another flashy bolt-on? After testing and hearing from real truck owners, we break it down.

🚀 What Is a FASS Fuel System?

Breakdown of how FASS separates air/vapor from diesel fuel

FASS stands for Fuel Air Separation System, and its main job is to deliver clean, pressurized fuel to your injection pump while removing air, water, and debris. It essentially improves the quality of fuel your engine burns, which can lead to:

Smoother idle
Better throttle response
Increased injector longevity
Slight fuel economy gains
Cleaner starts in cold weather

🔧 Why Upgrade Your 6.7 Power Stroke?

One of the weak spots of the 6.7 Power Stroke platform (especially in earlier models) is the CP4 injection pump, which can fail catastrophically and send metal shrapnel through the fuel system.

FASS doesn't replace the CP4 pump but helps protect it by filtering contaminants and preventing cavitation—a silent killer caused by air bubbles in fuel.

🛠️ Installation Notes

FASS system mounted near fuel tank/frame rail

Installation usually takes 4–6 hours, depending on your experience. Kits for the 6.7 Power Stroke come with all necessary hardware, but:

You may need to drop the tank for easier access.
Professional install is recommended if you’re not comfortable routing fuel lines or dealing with electrical connections.
Some models may require tuning adjustments to fully optimize performance.

📈 Performance Review – What Owners Say

Across forums and review sites, the FASS system receives high marks for reliability and noticeable improvements:

Throttle feels more responsive
Engine runs quieter and smoother
Cold starts are less rough
Better towing stability at lower RPMs

"After installing the FASS on my 2019 F-250, I noticed the truck no longer lags under load. It pulls smoother uphill, and idle quality improved dramatically." – Mike G., Powerstroke.org member

⚠️ Things to Consider Before Buying

Price: Ranges from $700–$1,100+ depending on the model and flow rate
Noise: Some users report pump noise when idling—location and rubber mounts can reduce this
Warranty Implications: Technically, modifying the fuel system can affect warranty claims, so check with your dealer

🏁 Final Verdict

For any 6.7 Power Stroke owner who wants reliability, better performance, and long-term protection, the FASS Fuel System is a solid investment. Whether you're towing heavy or just trying to extend your truck's life, this upgrade can give you peace of mind.