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.
- Keep driving?
- Short distances only
- DIY difficulty
- advanced
- Estimated cost
- $400-$5,000
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View pilot availability →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?
Run full aftertreatment test via IDS or ForScan.
Test both NOx sensors; they're the most common cause of false P20EE.
Inspect DEF injector spray pattern.
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:
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
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