Powertrain, generic (extended)

P230D Cylinder 4 Air-Fuel Ratio Imbalance - Adjustment At Limit During Balance

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P230D flags cylinder 4, so the engine needs at least four cylinders. The balancing function has run the individual fuel trim for that cylinder to its limit and the mixture still deviates. Audi's 2020 bulletin for the 2.0 TFSI (third-generation EA888) shows that this four-cylinder reports imbalance through the P230 series, which gives the code a real home, although the bulletin itself only names P230B and P230E. Mercedes lists irregular mixture formation at cylinder 4 among the faults caused by leaking valve seats on its M260/M264 four-cylinders. Swapping injector 4 with a neighbour shows whether the fault follows the injector; if it stays, look at intake sealing and compression. P219F and P0304 are the matching imbalance and misfire codes. The MIL comes on.

Likely causes

Injector of cylinder 4 delivering too much or too little (deposits, wear)
Air leak at the intake port or injector seal of cylinder 4
Valve of cylinder 4 not sealing (worn seat or guide), low compression
Poor contact at the connector of injector 4

Symptoms

  • Check engine light on
  • Rough idle, possibly misfire on cylinder 4
  • Higher fuel consumption or exhaust smell

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€0–1,500
Time0.5–6 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

fuel injector cyl 4intake manifoldcylinder compression

Related codes

P219FP230CP230EP0304P0204P219A

References: law.cornell.edu, static.nhtsa.gov, static.nhtsa.gov.