The Big Question: Is a 6.7 Cummins Delete Worth It?
Deleting a 6.7L Cummins (2007-2018) delivers major performance gains but comes with real legal risks. Here’s what you need to weigh before deciding:
The Benefits (Why People Delete)
- +30-50 HP & Torque (Removes DPF/EGR restrictions)- +2-4 MPG Gain (No more fuel-wasting regens)- Longer Engine Life (No soot recirculation = cleaner oil)- Eliminates $5,000 Repairs (DPF replacements, EGR cooler failures)
The Risks (Why Some Regret It)
- EPA Fines Up to $4,500 (If caught with tampered emissions)- Failed Inspections (In emissions-testing states)- Resale Value Impact (Some buyers avoid deleted trucks)- Warranty Void (If still under factory coverage)
Performance of Cummins Delete: What to Expect
1. Horsepower & Torque Increase
- Stock 6.7 Cummins: ~350 HP / 660 lb-ft
- Deleted + Tuned: 400-450 HP / 800+ lb-ft
- Biggest Gains: Turbo spools faster, no exhaust backpressure
2. Fuel Economy Improvement
- Before Delete: 14-16 MPG (with regens)
- After Delete: 16-20 MPG (no wasted fuel burning soot)
3. Engine Longevity
EGR delete stops:
- Carbon-clogged intake manifolds
- Coolant leaks from failed EGR coolers
DPF delete prevents:
- Turbo damage from backpressure
- Cracked pistons from high EGTs
Legal Risks: Is a Cummins Delete Legal?
Federal Law (EPA)
- Tampering with emissions = $4,500+ fine per violation
- Shops that perform deletes risk $37,500+ fines
- Enforcement increasing (especially in CA, TX, NY)
State Emissions Testing
- Strict States (Fail if deleted): CA, CO, NY, PA, etc.
- No-Test States (Safer): FL, OH, MI, most of the South
Resale & Warranty Issues
- Dealers may refuse CPO warranty
- Private buyers often pay less (unless it’s a performance market)
Alternatives to Full Deletes
If the legal risks worry you, consider:
DPF Cleaning ($300-$600)
- Extends DPF life but doesn’t fix underlying issues
EGR "Soft" Delete (Tune-Only)
- Keeps hardware intact but disables function via tuning
Partial Deletes (Mock DPF Shells)
- Maintains stock appearance but improves flow
Final Verdict: Who Should Delete?
Worth It If You:
- Live in a no-emissions-test state- Tow heavy and need reliability- Own an out-of-warranty truck- Accept the resale/fine risks
Not Worth It If You:
- Live in CA or strict emissions states- Have factory warranty remaining- Plan to sell to dealerships- Can’t afford potential fines
Thinking About Deleting? Do This First:
- Check local laws (Google “[Your State] diesel emissions testing”)
- Get quotes for repairs (Sometimes fixing emissions parts is cheaper)
- Research tuners (Some hide delete capability better than others)
FAQ
Can you undo a delete later?- Yes, but reinstalling DPF/EGR costs $2,000+ in parts.
What’s the #1 delete mistake?- Using cheap tuners that throw obvious CELs during inspections.
Are there “legal” deletes?- No – any tampering violates EPA rules, but enforcement varies.
What’s the cost of a 6.7 Cummins delete?- Expect $1,500-$3,500+ (kit + tuning + labor).
Bottom Line:
A 6.7 Cummins delete can boost performance, efficiency, and engine health, but the legal and financial risks are real. Weigh the pros and cons carefully before deciding!
