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P0021 on SUBARU IMPREZA

Severity
Medium
NHTSA Reports
5
Most Affected
2006, 2007, 2012

What P0021 Means on Your SUBARU IMPREZA

Real SUBARU IMPREZA Owner Reports (Source: NHTSA Complaints Database)

"Hard start, rough idle, drove 3 miles, check engine light turns on, code: p0021 bank1/2. did research. it's a banjo bolt filter/screen mine was cracked in half inside the oil line restricting oil to the turbo. managed to remove one easily accessible banjo screen which fixed half the problem."

— 2006 SUBARU IMPREZA owner • ENGINE • Filed 07/09/2020

"Purchased car august 20th. august 24th, 2013 on the way back from pa on 80 east my check engine light came on. problem was diagnosed as cam position timing over advance or system performance b1 and b2. code was p0011 and p0021."

— 2007 SUBARU IMPREZA owner • ENGINE • Filed 08/24/2013

"Code p0021 popped up shortly after engine had rattling noise and shut down."

— 2012 SUBARU IMPREZA owner • ENGINE • Filed 10/27/2020

"I have been having continuous problems with engine light coming on w the wheel skid light also. I went to Auto Zone and the codes P000D, C1422,P00700 and others."

— 2013 SUBARU IMPREZA owner • POWER TRAIN,UNKNOWN OR OTHER,ENGINE • Filed 07/22/2023

"I own a 2014 Subaru Impreza WRX which was still under warranty(48xxx miles) I’ve been having issues with my vehicle where at times it shuts off on me whenever I come to a complete stop."

— 2014 SUBARU IMPREZA owner • ENGINE • Filed 08/13/2021

Data from NHTSA Vehicle Complaints Database. All reports are filed by vehicle owners directly with the U.S. Department of Transportation.

Common Causes of P0021 on SUBARU IMPREZA

80%
20%

Percentages based on NHTSA complaint component analysis for this vehicle.

Complaint Trend by Year

2006
1
2007
1
2012
1
2013
1
2014
1

What To Do Next

  1. 1
    Check for recalls on YOUR VIN

    Go to nhtsa.gov/recalls and enter your VIN. Free repairs if your vehicle is covered.

  2. 2
    Get a proper diagnosis

    A code alone doesn't tell you the exact failed part. A diagnostic at a shop ($50-$150) pinpoints the root cause before you spend money on parts.

  3. 3
    Compare repair quotes

    Get 2-3 quotes. Dealer vs independent shop prices often differ 30-50% for the same repair.

P0021 on Other Vehicles

Data sourced from the National Highway Traffic Safety Administration (U.S. Department of Transportation) and the SAE J2012 OBD-II standard. Code definitions follow the SAE J2012 / ISO 15031-6 standard. Owner reports are filed directly with NHTSA by vehicle owners. This information is provided for educational purposes only and should not replace professional automotive diagnosis. Always consult a qualified mechanic for vehicle repair decisions.

Last updated: March 2026