Fuel and injectionGeneric OBD-II codeUrgency: Garage soon

P2188 on Ford: causes and affected engines

P2188 means: too rich at idle (bank 1).^[1][2][3] Ford has 9 documented faults that can trigger it, across 8 engines, including 1.4 HDi, 1.6 HDi, 1.3 Multijet and 1.8 TDCi. Only a diagnosis can confirm the cause on your car.

Documented faults

that can trigger it

Engines

used by Ford, with at least one of them

Ford models

with at least one of these faults

Urgency

Garage soon

Reviewed on 31 October 20263 sources How we work

Documented faults in Ford engines that can trigger P2188

Grouped by engine or model, from most to least important. These are faults with the injectors, of the mass airflow sensor, of the lambda sensor and of the catalytic converter: not all of them will necessarily set the code, and only a diagnosis confirms the cause on your car.

1.4 HDi

In Fiesta V, Fiesta VII and Fusion

- Medium severityFrequency: Very frequentInjectionInjectors that lose their seal and let diesel escapeThe most cited weak point of the 1.4 HDi is its injectors: over time they can lose their seal and let diesel escape, which is usually noticed as a smell of diesel in the car. It appears in the two most common outputs (68 and 70 hp) and in both cases it is identified as the engine's main weakness.

1.6 HDi

In B-Max, C-Max I, C-Max II, Fiesta VII, Focus II, Focus III and Transit Connect

1.3 Multijet

In Ka II

- High severityFrequency: OccasionalInjectionInjector and high-pressure pump wear from contaminated fuelThe Bosch injectors and the high-pressure pump of the common rail system are sensitive to poor-quality fuel or fuel with condensed water. With contaminated diesel they can generate metal shavings that damage first the pump and then the injectors themselves.Repair (garage): €600–€1,200

1.8 TDCi

In C-Max I, Focus I, Focus II, Galaxy II, Mondeo III, Mondeo IV and 2 more models

- Medium severityFrequency: CommonInjectionDelphi injector failure (leaks, cracks or poor spray pattern)The 1.8 TDCi's Delphi injectors can crack, drip or spray diesel poorly over time, causing hard starting, smoke and jerking. It is a recurring fault, documented from 45,000 km in the Focus and up to 130,000 km in the Mondeo.Appears at around 45,000 km

2.2 HDi

In Mondeo IV

- High severityFrequency: OccasionalInjectionPiezo injector wear and failureThe 2.2 HDi uses third-generation common-rail injection with piezo injectors at up to 1,800-2,000 bar. Fiches-auto documents injector cases across several power outputs, without it being the most repeated fault, with symptoms of hard starting, jerking or higher fuel consumption.

1.2 8v Fire

In Ka II

- Medium severityFrequency: OccasionalElectronicsSensor failures: lambda sensor and crankshaft position sensor (TDC)The 1.2 8v Fire can suffer sensor faults: the lambda sensor (warning light, rough running) and, in the Fiat Punto, the crankshaft position sensor (TDC sensor), linked to misfires. These are minority issues, but they recur across several models with this engine.

2.2 / 2.4 / 3.2 TDCi (Puma)

In Tourneo Custom, Transit VI-VII, Transit and Transit Custom

- Medium severityFrequency: OccasionalInjectionFaulty injectors on the 2.2 and 2.4 TDCiHaynes documents faulty injectors on the 115 hp Transit 2.2 and the 140 hp 2.4, and L'argus reports an injector recall on the 2014-2015 Boxer and Jumper 2.2 HDi. They cause rough idle, loss of power or stalling.

1.5 / 2.0 EcoBlue

In Fiesta VIII, Focus IV, Galaxy III, Kuga III, Mondeo V, Puma and 7 more models

- Medium severityFrequency: RareEmissions controlEmissions system warnings (AdBlue/EGR) and injector wearOn the Ford Focus IV and Kuga III, generations that now only use EcoBlue, some owners report, occasionally (not in the majority), AdBlue system warnings or injector failures. It is a small sample, and we have not found that Ford has announced a campaign of its own for the EcoBlue for this reason.

Common causes of P2188 on any make

From most to least likely, according to the sources.

1Fuel pressure too high due to a stuck or faulty regulator.^[1][2]
2Injector leaking or dripping, which adds unmetered fuel at idle.^[1][2]
3Dirty, faulty or over-reading mass airflow meter.^[1][2]
4Upstream lambda sensor contaminated or slow.^[1][2]

What to check first

The first diagnostic steps, from the most likely and cheapest to check to the most expensive.

1With the engine warm, read the idle fuel trims on the scanner. Confirm that the long-term adjustment is strongly negative at idle and returns to normal on acceleration, and check whether the code is active or only in the history.^[1]
2Measure the fuel pressure at idle and after switching the engine off. According to AutoDTCs, pressure above the specification points to the regulator; if it falls slowly, to a leaking injector; and if it drops suddenly, to the pump's non-return valve.^[1]
3Test the purge valve and the injectors: command the valve to close and check whether the negative adjustment reduces; carry out an injector balance test and look for uneven speed drops or dripping.^[1]

Full guide to P2188: symptoms, diagnosis and whether you can drive

Parts related to code P2188 on Ford cars

The parts that most often cause this code. The code points to the circuit, not always the part: diagnose before you buy.

Injector
- Buy part at Autodoc (affiliate link, opens in a new tab)

Affiliate links: if you buy from these shops, MotorFiable may receive a commission at no cost to you. Check compatibility against the registration plate or VIN before ordering. Affiliate links

Frequently asked questions

Which Ford engines have faults that can trigger P2188?

1.4 HDi (1 fault), 1.6 HDi (2 faults), 1.3 Multijet (1 fault), 1.8 TDCi (1 fault), 2.2 HDi (1 fault) and 1.2 8v Fire (1 fault). Each fault has its own page with the affected years and versions, the symptoms and the repair cost.

What does code P2188 mean on a Ford?

Too rich at idle (bank 1). Bank 1 runs with excess fuel only at idle and at low load. The control unit responds by removing fuel through a negative long-term adjustment, and the code is stored when, at idle, that adjustment stays at its rich limit for long enough without the oxygen sensor managing to correct it. It is a generic OBD-II code: it means the same on a Ford as on any other make.^[1][2][3]

Can I keep driving with P2188?

Garage soon. AutoDTCs rates it as moderate severity: the car can usually be driven, but it is worth repairing soon to protect the catalytic converter, because a sustained rich mixture fouls the spark plugs and eventually loads the catalytic converter with soot.^[1]

Sources

Every fact on this page links to its source. If you find an error, let us know.

P2188 – System Too Rich at Idle Bank 1 — AutoDTCsAutoDTCs · Technical documentation · published August 2026 · consulted 31 October 2026
OBD DTC Fehlercode P2188 | System im Leerlauf zu fett, Bank 1CarWiki.de · Technical documentation · consulted 31 October 2026 · in German
p2188 Generic DTC: System Too Rich at IdleDTCSearch.com (OBD Solutions) · Technical documentation · consulted 31 October 2026