POWERSTROKE-P20EE serious Power Stroke ›

SCR NOx Catalyst Efficiency Below Threshold Bank 1

The POWERSTROKE-P20EE (Power Stroke) diesel fault code means: SCR NOx Catalyst Efficiency Below Threshold Bank 1. This is a serious severity code.

Unverified. We could not confirm this code's definition against freely available manufacturer documentation, so treat the meaning, severity and fix guidance on this page as unconfirmed. Check it against the manufacturer's service information for your exact model and serial range before acting on it. This page is kept out of search engines for that reason, and we are working through this family manual by manual.

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Keep driving?
Short distances only
DIY difficulty
advanced
Estimated cost
$400-$5,000
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What Are the Symptoms of POWERSTROKE-P20EE?

  • CEL
  • Derate warning/countdown
  • Poor emissions performance

What Causes POWERSTROKE-P20EE? (Most Likely First)

  • Aged / poisoned SCR catalyst Very Likely
  • Failed NOx sensor giving false efficiency data Likely
  • Cracked DEF injector crystallizing urea Likely
  • Engine over-fueling causing excess NOx Possible

Can I Still Drive with POWERSTROKE-P20EE?

Short distances only. POWERSTROKE-P20EE is rated serious severity. Keep trips short and get it diagnosed soon rather than waiting for symptoms to worsen.

Frequently Asked Questions

What is P20EE on a 6.7L Power Stroke (Scorpion)?

P20EE on a 6.7L Power Stroke (Scorpion) (2011-present) indicates: SCR NOx Catalyst Efficiency Below Threshold Bank 1. This is a known diagnostic trouble code on this engine family and typically points to the causes listed above.

Can I drive with P20EE on my Power Stroke?

Only drive short distances to get to a repair facility. Continued operation may cause further damage.

How much does it cost to fix P20EE?

Repair cost is typically $400-$5,000 depending on the underlying cause and whether you DIY or use a shop. Diagnostic time alone runs $100-$180 at most independent diesel shops.

Mechanics Guide Step-by-step diagnosis

How Do You Diagnose POWERSTROKE-P20EE?

  1. Run full aftertreatment test via IDS or ForScan.

  2. Test both NOx sensors; they're the most common cause of false P20EE.

  3. Inspect DEF injector spray pattern.

  4. If SCR cat is truly spent, replacement is $2,000-$5,000 typically.

Sources 1

This page is built from documented references. Verify against your own service info before repair work.

  • SAE J2012Diagnostic Trouble Code Definitions (defines P20EE as a generic OBD-II code)

P20EE on Other Platforms

The same code ID appears across other engines, vehicles, and equipment. Diagnostic flow varies by platform — see the matching breakdown:

Bobcat serious SCR NOx Catalyst Efficiency Below Threshold (Bank 1) Duramax critical SCR NOx Catalyst Efficiency Below Threshold Bank 1 Hino serious NOx Converting Catalyst Conversion Efficiency Isuzu serious Diesel Exhaust Fluid (DEF) System NOx Trap Low Efficiency Kubota serious SCR NOx Catalyst Efficiency Below Threshold - Bank 1 Yanmar serious SCR NOx Catalyst Efficiency Below Threshold

Which Vehicles Commonly Get POWERSTROKE-P20EE?

  • 2011-present Ford F-250 Super Duty 6.7L Power Stroke
  • 2011-present Ford F-350 Super Duty 6.7L Power Stroke
  • 2011-present Ford F-450/F-550 Super Duty 6.7L Power Stroke
  • 2015-2019 Ford F-650/F-750 6.7L Power Stroke

Explore More

More Power Stroke codes → Diesel home All diesel codes Heavy-duty Guides

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