P2000Emissions / Exhaust

NOx Trap Efficiency Below Threshold Bank 1

P2000 means the NOx trap (lean NOx trap or NOx adsorber) on Bank 1 is not storing and reducing nitrogen oxides efficiently. It is common on diesel and some lean-burn engines. Causes include a saturated or aged NOx trap, a NOx sensor fault, or a failed regeneration cycle.

🚗 Yes, but the vehicle will not meet emissions standards and the trap should be serviced.

MEDIUM

severity

🎯 Top Causes, Ranked by Likelihood

#1Aged or saturated NOx trap/catalyst$500-$2000

40%

The trap has lost storage capacity from age, sulfur poisoning, or contamination.

#2Faulty NOx sensor$200-$600

30%

A bad NOx sensor gives incorrect efficiency readings.

#3Failed regeneration or fuel dosing issue$100-$800

20%

The trap cannot regenerate properly to clear stored NOx.

#4Exhaust leak or restricted flow$100-$600

10%

Leaks or restrictions upset the NOx measurement.

🩺 Common Symptoms

Check engine light on
Possible reduced power or limp mode
Increased emissions
Will fail an emissions test

💰 Repair Cost: DIY vs Shop

DIY Cost

$200-$1000

Shop Cost

$500-$2500

📋 Free OBD2 Code Cheat Sheet

The 50 most common codes with likely cause and DIY fix cost. Sent once, no spam.

🔧 How to Diagnose P2000

1Scan for related NOx and regeneration codes

2Check NOx sensor readings against known good data

3Inspect the exhaust for leaks and restrictions

4Verify regeneration cycles complete and fuel dosing works

❓ Frequently Asked Questions

Can I drive with a P2000 code?

Usually yes for short trips, but some vehicles enter limp mode. The car will not pass emissions, so repair it soon.

How much does it cost to fix P2000?

A NOx sensor may be $200 to $600, but a new NOx trap can run well over $1000 at a shop.

What is the most common cause of P2000?

An aged or saturated NOx trap is the most common cause, often paired with a faulty NOx sensor.

🔗 Related Codes

P2001P2002P2003P20EEP0420