P2171 moderate

EGR Throttle Position Sensor (Bank 2) Circuit

The P2171 code means the vehicle's onboard diagnostic system has detected: EGR Throttle Position Sensor (Bank 2) Circuit. This is a moderate severity code.

My Garage →

Keep driving?: Yes, but fix soon
DIY difficulty: moderate
Estimated cost: $80 - $400 (parts and labor)

Recommended Tool

ANCEL AD310 OBD-II Scanner

Best-selling code reader on Amazon. Reads and clears check engine codes on any 1996+ vehicle. Under $30.

Check Price on Amazon

Affiliate link -- we earn a commission at no extra cost to you.

Every Tech Needs This

AstroAI Digital Multimeter

Essential for diagnosing sensor codes, checking voltage, and testing circuits. Under $15 and pays for itself on the first job.

Check Price on Amazon

Affiliate link -- we earn a commission at no extra cost to you.

Common Symptoms

Check Engine Light on
Rough idle
Increased NOx emissions
Failed emissions test
Slight hesitation during acceleration

Probable Causes (Ranked by Likelihood)

Failed EGR throttle position sensor Very High
Wiring damage to EGR TPS High
Carbon buildup on EGR valve affecting sensor Moderate
ECM EGR input circuit fault Low

Step-by-Step Diagnostic Procedure

Read EGR position sensor data on scan tool
Inspect EGR valve and sensor for carbon buildup
Measure EGR TPS reference voltage and signal
Clean EGR valve and retest sensor operation

Frequently Asked Questions

What does P2171 mean?

P2171 indicates: EGR Throttle Position Sensor (Bank 2) Circuit. The ECM detected an abnormal condition in this sensor circuit.

Is P2171 serious?

Moderate. The vehicle may enter limp mode. Repair promptly.

What should I check first?

Start with a visual inspection of the sensor wiring and connector. Use a scan tool to read sensor data and compare to expected values. Check reference voltage (typically 5V) at the sensor connector.