SCR NOx Catalyst Efficiency Below Threshold (Bank 1)
The BOBCAT-P20EE (Bobcat) diesel fault code means: SCR NOx Catalyst Efficiency Below Threshold (Bank 1). This is a serious severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- advanced
- Estimated cost
- $300-$3,500
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Common Symptoms
- Derate warning / 3-stage inducement countdown
- CEL and DEF lamp
Probable Causes (Ranked by Likelihood)
- Contaminated DEF fluid (wrong fluid / water) Likely
- Failed downstream NOx sensor Likely
- Plugged / aged SCR catalyst Possible
Step-by-Step Diagnostic Procedure
Test DEF fluid with refractometer (32.5% urea).
Scan NOx sensor outputs upstream/downstream during load.
Check SCR inlet NH3 dosing via Service Analyzer.
Frequently Asked Questions
What is Bobcat code P20EE?
Bobcat P20EE: SCR NOx Catalyst Efficiency Below Threshold (Bank 1). This code is reported on Bobcat equipment running the described engine family.
Can I keep working with Bobcat code P20EE?
Limited operation only -- finish the current task then shut down for repair.
How much does Bobcat P20EE cost to fix?
Typical repair cost: $300-$3,500. Off-road diesel shop labor runs $125-$175/hr in 2026. Dealer diagnostic software (Bobcat Service Analyzer) is usually required.
P20EE on Other Platforms
The same code ID appears across other engines, vehicles, and equipment. Diagnostic flow varies by platform — see the matching breakdown: