What Does P0172 Mean on Your 2020 Dodge Challenger?
A P0172 code on your 2020 Dodge Challenger means the PCM has detected a rich fuel condition on Bank 1. The 2020 Challenger is available with the 3.6L Pentastar V6 (303 hp), the 5.7L HEMI V8 (375 hp), the 6.4L 392 HEMI V8 (485 hp), or the supercharged 6.2L Hellcat (717-797 hp). Bank 1 is the driver's side cylinder bank on all V-engines.
The Challenger is a performance machine, and a rich condition robs it of efficiency and crispness. Whether you cruise in a V6 or roar in a Hellcat, getting this resolved restores your Challenger to peak form.
Symptoms You Might Notice
- Check engine light on
- Reduced fuel economy
- Rough or lumpy idle
- Black smoke from the exhaust, especially under load
- Strong fuel smell at the tailpipe
- Reduced throttle crispness
Common Causes of P0172 on the 2020 Dodge Challenger
- Contaminated MAF Sensor — Challengers are popular modification platforms, and aftermarket cold air intakes with oiled filters are the number one source of MAF contamination.
- Stuck-Open EVAP Purge Valve — A known Mopar issue. The purge solenoid fails and floods the intake with fuel vapors.
- Degraded O2 Sensor — The upstream oxygen sensor on Bank 1 may respond slowly or read incorrectly.
- Leaking Fuel Injector — HEMI injectors, especially on MDS-equipped engines, can develop seal issues from thermal cycling.
How to Diagnose the Problem
- Pull all DTCs — Look for P0175, MAF, O2, or EVAP companion codes.
- Compare fuel trims — Bank-specific analysis reveals whether the issue is localized or systemic.
- Test MAF sensor output — Compare to factory specs at idle and under load.
- Test the purge valve — Command open/close and verify proper sealing.
- Monitor O2 sensor — Check voltage oscillation speed and range.
- Test fuel injectors — Cylinder balance test.
Repair Options and Cost Estimates
- MAF Sensor Cleaning — DIY: $10-$15. Shop: $55-$110.
- MAF Sensor Replacement — Parts: $70-$175, labor: $55-$110. Total: $125-$285.
- Purge Valve Replacement — Parts: $25-$60, labor: $55-$110. Total: $80-$170.
- O2 Sensor Replacement — Parts: $70-$185, labor: $90-$170. Total: $160-$355.
- Fuel Injector Replacement — Parts: $45-$140 each, labor: $180-$380. Total: $225-$520.
Can You Fix This Yourself?
Absolutely. The Challenger's large engine bay (especially on the V8) makes DIY work easy. MAF cleaning takes 15 minutes. Purge valve replacement is a half-hour job. If you have an aftermarket intake, remove and clean the MAF, and make sure the filter isn't over-oiled. O2 sensor access from underneath is also straightforward.
Prevention Tips
- If using an aftermarket intake, oil the filter sparingly and let it dry before installing
- Replace the stock air filter at recommended intervals
- Use premium fuel for HEMI and Hellcat engines
- Monitor fuel economy — sudden drops signal developing issues