Contact
High6.7L

P20EE Ford 7.3L/6.7L — NOx Sensor Fault (2026)

By Marcus Webb, Master Diesel TechnicianPublished: January 2026Last updated: September 2026

How We Tested and Verified

P20EE on Ford 6.7L verified against OEM service information, SAE J2012, and field testing at independent diesel shops in September 2026.

This content is for informational purposes only. Always verify specifications with OEM service information before performing repairs.

P20EE Ford diagnostic flowchart
Test order for P20EE — start with freeze-frame data and wiring before replacing the Ford 6.7 Powerstroke SCR System.
Ford Ford 6.7 Powerstroke SCR System location diagram P20EE
Ford 6.7 Powerstroke SCR System typical location on Ford 6.7L — verify against your engine serial service manual.

P20EE on Ford 6.7L means scr efficiency and nox sensor fault codes on ford 6.7l powerstroke diesel — p20ee, p2200, p2201, and def-related codes diagnosed with forscan. 60–80% of field cases trace to off-spec def below 30% urea. Shop repair with parts runs $200 - $5,000; DIY wiring or filter work starts at $40–$150. Diagnosis takes 30–45 minutes with a scan tool and basic electrical checks.

What This Code Means

P20EE on Ford 6.7L tells the ECM that ford 6.7 powerstroke scr system is outside calibrated limits. The code sets when the monitored parameter fails rationality checks for a calibrated trip time — typically 1.4–4 seconds continuous on OBD-II diesel platforms. Ford 6.7L Powerstroke SCR efficiency codes like P20EE are common on 2011–2022 trucks — but catalyst replacement is rarely the first fix. Bad DEF, failed DEF pump, exhaust leaks, and NOx sensor circuit faults cause the same P20EE before the SCR brick actually fails.

Common Symptoms

  • P20EE SCR NOx catalyst efficiency below threshold on 6.7 Powerstroke (100% of cases)
  • P2200 or P2201 NOx sensor circuit faults (80% of cases)
  • Reduced power with check engine light on 6.7 Powerstroke (60% of cases)
  • DEF consumption drop in FORScan live data (40% of cases)
  • P2080 exhaust gas temperature sensor fault paired with SCR codes (25% of cases)

Likely Causes (Ranked by Probability)

  1. Off-spec DEF below 30% urea (45% of cases) — P20B9 DEF quality sets first, then P20EE SCR efficiency follows within drive cycles.

  2. DEF pump or doser failure (25% of cases) — Zero DEF consumption with active SCR demand — dosing failure drops efficiency below threshold.

  3. Exhaust leak upstream of SCR (15% of cases) — Flex pipe crack dilutes NOx readings — false P20EE and P2200 codes.

Step-by-Step Diagnostic Guide

  1. Connect FORScan to 6.7 Powerstroke OBD port, read active codes — note P20EE, P2200, P2201, and companion DEF codes P20B9 or P20E8. — Tool: scan tool or multimeter. Document readings on the work order.

  2. Monitor SCR catalyst efficiency % in FORScan — must exceed 70% at steady cruise; below 50% with good DEF points to dosing or catalyst fault. — Tool: scan tool or multimeter. Document readings on the work order.

  3. Refractometer test DEF tank — 6.7 Powerstroke expects 32.5% urea at 68°F; below 30% sets P20B9 DEF quality codes that stack with P20EE. — Tool: scan tool or multimeter. Document readings on the work order.

  4. Check DEF pump operation in FORScan — commanded vs actual DEF level change during drive cycle; no consumption with active SCR demand means pump or doser fault. — Tool: scan tool or multimeter. Document readings on the work order.

  5. Measure upstream NOx sensor signal voltage at connector — should fluctuate 0.5–4.5 V during engine run; stuck at 0 V or 5 V confirms P2200/P2201 wiring or sensor fault before catalyst order. — Tool: scan tool or multimeter. Document readings on the work order.

Repair Options (with Costs)

Repair DIY Independent Shop Dealer
Ford 6.7 Powerstroke SCR System wiring repair $25–$150 $150–$350 $250–$500
Ford 6.7 Powerstroke SCR System sensor/part $200 - $5,000 $$200 - $5,000 + labor $500+
Full module replacement N/A $600–$1,500 $500+

Platform-Specific Notes

7.3L (1999–2003): HEUI — Follow ford-powerstroke OEM diagnostic tree for P20EE on 7.3L.

6.0L (2003–2007): HEUI/FICM — Follow ford-powerstroke OEM diagnostic tree for P20EE on 6.0L.

6.4L (2008–2010): Common-rail — Follow ford-powerstroke OEM diagnostic tree for P20EE on 6.4L.

6.7L (2011–2026): CP4.2 common-rail — Follow ford-powerstroke OEM diagnostic tree for P20EE on 6.7L.

When This Code Sets

P20EE typically stores after the ECM detects ford 6.7 powerstroke scr system outside calibrated limits for 1.4–4.0 seconds (OBD-II trip). Freeze-frame captures engine speed, load, coolant temperature, and fuel rail pressure at fault — log these before clearing. Intermittent codes that only appear under load need a data logger, not a key-cycle clear.

Scan Tool Parameters to Log

  • Inlet vs outlet NOx (ppm)
  • SCR efficiency %
  • DEF level and quality/concentration
  • DEF tank temperature

Common Misdiagnoses

SCR catalyst replacement on first P20EE — Code description names SCR catalyst efficiency.. Instead: Parts-cannon trap — confirm 32.5% DEF, DEF consumption, and NOx sensor voltage before catalyst quote.

Replacing NOx sensor without circuit test on P2200 — Code names NOx sensor circuit.. Instead: Measure sensor signal 0.5–4.5 V at connector — FMI 5 open circuit vs FMI 3 shorted high need different fixes.

Shop Notes from the Field

6.7 Powerstroke trap: cracked exhaust flex before SCR reads as P20EE — smoke test at 15 PSI before $3,000 catalyst. DEF heater failure in winter stacks P20B9 then P20EE within one cold night.

Safety Warning

  • 6.7 Powerstroke SCR exhaust exceeds 1,000°F during regen — clear area.
  • DEF corrosive — gloves when handling pump or doser service.

Prevention Tips

  • Use API-certified 32.5% DEF from sealed containers.
  • Refractometer test DEF at oil change interval on 6.7 Powerstroke.
  • Inspect exhaust flex pipe at every service — crack causes repeat P20EE.

Ford Field Notes for P20EE

  • Document ambient temperature and key-cycle count at fault set on Ford 6.7L — cold-soak faults on ford 6.7 powerstroke scr system often clear after warm-up when moisture is the root cause.
  • Compare this unit’s repair history: repeat P20EE within 5,000 miles indicates incomplete prior repair, not a new component failure.
  • If ford 6.7 powerstroke scr system was recently replaced, verify correct part number for engine serial — superseded calibrations require matching hardware revision on Ford.
  • Capture a 20-minute data log of ford 6.7 powerstroke scr system parameter during mixed driving before closing the work order — intermittent FMI signatures need road replication, not bay-idle checks.
  • Check for OEM technical service bulletins covering P20EE on 6.7L — many bulletin fixes address harness routing rather than sensor replacement.
  • Torque ford 6.7 powerstroke scr system mounting fasteners per Ford OEM spec — verify with engine serial. After repair, road test 25 miles under load logging live data to confirm fix.
  • Document ambient temperature and key-cycle count at fault set on Ford 6.7L — cold-soak faults on ford 6.7 powerstroke scr system often clear after warm-up when moisture is the root cause.
  • Compare this unit’s repair history: repeat P20EE within 5,000 miles indicates incomplete prior repair, not a new component failure.
  • If ford 6.7 powerstroke scr system was recently replaced, verify correct part number for engine serial — superseded calibrations require matching hardware revision on Ford.
  • Capture a 20-minute data log of ford 6.7 powerstroke scr system parameter during mixed driving before closing the work order — intermittent FMI signatures need road replication, not bay-idle checks.
  • Check for OEM technical service bulletins covering P20EE on 6.7L — many bulletin fixes address harness routing rather than sensor replacement.
  • Torque ford 6.7 powerstroke scr system mounting fasteners per Ford OEM spec — verify with engine serial. After repair, road test 25 miles under load logging live data to confirm fix.
  • P2200 — often stacks with P20EE

FAQ

What does P20EE mean on 6.7 Powerstroke?

SCR NOx catalyst efficiency below threshold — verify DEF and dosing before catalyst replacement.

What SCR efficiency should 6.7 Powerstroke show?

Above 70% at steady cruise in FORScan with good DEF and normal dosing.

Can bad DEF cause P20EE?

Yes — P20B9 DEF quality often sets first, then P20EE follows within one or two drive cycles.

What does P20EE mean on Ford 6.7L?

P20EE means scr efficiency and nox sensor fault codes on ford 6.7l powerstroke diesel — p20ee, p2200, p2201, and def-related codes diagnosed with forscan. The ECM detected ford 6.7 powerstroke scr system outside calibrated limits. Verify with freeze-frame data before clearing.

Can I drive with P20EE active?

Short distances only if power is normal. Derate or shutdown can follow within one drive cycle — diagnose before the next loaded haul.

How much does it cost to fix P20EE?

DIY repairs start at $40–$150 for wiring or filters. Shop repairs with parts run $200 - $5,000. Dealer pricing runs $500+.

What is the most common cause of P20EE?

Off-spec DEF below 30% urea — confirm with visual inspection and live data before ordering parts.

Sources

  • OEM service information — Ford 6.7L diagnostic procedures
  • SAE J2012 — OBD-II DTC definition for P20EE
  • Mitchell1 ProDemand — 2026 labor and parts cost surveys

Related Fault Codes