What Does P0174 Mean on Your 2021 Jeep Gladiator?
A P0174 code on your 2021 Jeep Gladiator indicates that Bank 2 of the 3.6L Pentastar V6 engine is running too lean. The PCM has been adding extra fuel to compensate for an air-heavy mixture, but it has exceeded its correction range.
Symptoms You Might Notice
- Check engine light on the dash
- Rough or shaky idle
- Hesitation when accelerating, especially with a load
- Reduced fuel economy
- Occasional stalling at idle
- Hissing noise from the engine bay
Common Causes of P0174 on the 2021 Gladiator
The Gladiator shares its 3.6L Pentastar V6 with the Wrangler. Being a truck that often sees off-road and towing duty, certain issues are more common:
- Vacuum Leak — Intake manifold gaskets, vacuum hoses, and the PCV valve can develop leaks. Off-road vibration and heat cycling accelerate wear on these components.
- MAF Sensor Contamination — Dusty driving conditions and off-road use can contaminate the mass airflow sensor faster than normal.
- Fuel Injector Issues — Clogged or partially stuck injectors on Bank 2 reduce fuel delivery. Towing and heavy loads stress the fuel system.
- Weak Fuel Pump — The in-tank electric fuel pump can weaken, particularly if the truck is frequently operated at low fuel levels.
How to Diagnose the Problem
- Scan all codes and review freeze frame data.
- Monitor Bank 2 fuel trims with a live scan tool. LTFT above +10% confirms lean running.
- Inspect all vacuum hoses, intake gaskets, and the PCV system.
- Smoke test the intake for hidden leaks.
- Test fuel pressure at the rail — expect 55-62 PSI on the 3.6L Pentastar.
- Clean the MAF sensor and compare readings to spec.
Repair Options and Estimated Costs
- Vacuum leak repair: $100–$400. Replace worn hoses and gaskets.
- MAF sensor replacement: $120–$300. Easy DIY fix.
- Fuel injector cleaning or replacement: $250–$600. Professional cleaning is recommended.
- Fuel pump replacement: $450–$800 with parts and labor.
Can You Still Drive?
Light driving around town is okay, but avoid towing and heavy payloads. Running lean under load increases combustion temperatures and risks catalytic converter damage, which costs over $1,000 to replace on the Gladiator.
Prevention Tips
- Change the air filter more frequently if you drive off-road or in dusty conditions.
- Inspect vacuum hoses and connections after trail rides.
- Use quality fuel and consider a fuel system treatment every 5,000 miles.
- Do not regularly run the fuel tank below a quarter full — this stresses the fuel pump.
- Address check engine lights promptly.