2022-2026 Audi MIL On, Misfire, Lean Fuel System DTCs

Symptoms

Owners of various Audi models from 2022-2026 may experience a range of symptoms related to fuel quality issues, often accompanied by the illumination of the Malfunction Indicator Lamp (MIL). These symptoms include:

• Excessive accumulation of deposits on intake valves, intake manifold, fuel injectors, and combustion chambers.
• The engine running rough after a cold start.
• Excessive engine cranking time.
• Hesitations while driving.
• Rough engine idle.
• Reduced engine performance.
• Poor fuel economy.

Fault Codes / DTCs

When these conditions are severe enough to illuminate the MIL, the Engine Control Module (ECM), specifically J623 (address word 0001), may store one or more of the following Diagnostic Trouble Codes (DTCs):

Code	Description
P0300	Random/Multiple Cylinder Misfire Detected
P030x	Specific Cylinder Misfire Detected
P0171	System Too Lean (Bank 1)
P0174	System Too Lean (Bank 2)
P1128	Oxygen Sensor Heater Circuit Malfunction
P1130	Oxygen Sensor Heater Circuit Malfunction
P1136	Oxygen Sensor Heater Circuit Malfunction
P1138	Oxygen Sensor Heater Circuit Malfunction
P219C00	Air/Fuel Ratio Imbalance
P219D00	Air/Fuel Ratio Imbalance
P219E00	Air/Fuel Ratio Imbalance
P219F00	Air/Fuel Ratio Imbalance
P21A000	Air/Fuel Ratio Imbalance
P21A100	Air/Fuel Ratio Imbalance

Diagnosis / Trigger Conditions

This TSB, 01 24 48 2014753/13, identifies the primary cause of these issues as the use of contaminated gasoline or gasoline with a low content of deposit control additives. Contaminated gasoline may have a unique color and odor, contain undissolved water, sediments, or appear cloudy. Fuel lacking sufficient deposit control additives leads to carbon buildup on critical engine components.

For MY2016-MY2019 Audi vehicles equipped with the 3.0TFSI EVO (CREC) engine, specific deviations in fuel quality can lead to deposits forming in the injectors. These deposits can prevent proper injector closure, causing fuel to enter the intake manifold or cylinder after the engine is switched off, leading to an overly rich mixture upon subsequent starts.

Important Warnings

Audi has issued specific warnings regarding this issue:

• Do not replace injectors for this issue. The TSB explicitly states that replacing injectors will not resolve the problem, particularly for MY16-MY19 3.0TFSI EVO (CREC) equipped vehicles where deposits are the root cause.
• The use of gasoline additive G 001770A2 is not reimbursed under warranty. Owners should be aware that while this additive is recommended for treatment, its cost is not covered under warranty.

Repair Procedure Summary

The recommended repair focuses on addressing the fuel quality and deposit buildup. For general cases, Audi recommends using gasoline additive G 001770A2 to remove existing carbon deposits from injectors (MPI and FSI engines), combustion chambers (MPI and FSI engines), and intake valves (MPI engines only).

The additive should be mixed directly into a full fuel tank. The recommended ratio is 60 ml per 20 liters of gasoline, or 120 ml per 10 gallons of gasoline.

For MY2016-MY2019 3.0TFSI EVO (CREC) equipped vehicles, a specific additive, G 001780M3 (200 ml), should be used. This multi-purpose additive helps remove deposits from low- and high-pressure injectors and ensures their proper sealing. If the issue persists after using the additive, further diagnosis should be performed. For detailed instructions on removing carbon deposits from intake valves of FSI engines, refer to TSB 2019948, which addresses '01 MIL on (P0300 and/or P0301 - P0306 stored in ECM)'.

Required Parts

To address the conditions described in TSB 01 24 48 2014753/13, the following parts may be required:

• Gasoline Additive G 001770A2: For general carbon deposit removal.
• Gasoline Additive G 001780M3: Specifically for MY2016-MY2019 3.0TFSI EVO (CREC) engines.
• Fasteners, Bolts, Nuts, and Screws: As needed per the repair manual, referenced via ETKA/ELSA.

Owner Action

If your Audi is experiencing a 'MIL on' light, misfires, or lean fuel system DTCs, particularly a 2022 Audi e-tron with a P0300 code, it is recommended to first consider your fuel source. Switching to TOP TIER Detergent Gasoline can help prevent and reduce carbon deposits. If symptoms persist, consult with an authorized Audi service center. Be aware that the cost of gasoline additive G 001770A2 is not covered under warranty.

NHTSA ID: 11012476