Is a 6.7 Cummins Delete Worth the Cost? Performance vs. Legal Risks

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!