22/08/2026 10:39 am
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Automotive Q&A
P0302 moved after an injector swap—what should be checked before replacement?
Review the evidence, add a focused answer, and distinguish confirmed measurements from assumptions.
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A 2016 Kia Sorento 3.3L had a consistent cylinder 2 misfire at idle with P0302. Relative compression was even, ignition coils and plugs did not move the fault, and there was no intake leak at that runner. After swapping injectors 2 and 4, the misfire counter and code moved to cylinder 4.
That strongly implicates the injector, but before ordering one I want to rule out anything introduced by the swap. Which connector, seal, rail and fuel checks should be repeated so the conclusion is supported and the replacement does not create a leak?
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23/08/2026 7:17 am
A fault that follows the injector is strong A/B evidence. Reinspect both connectors for pushed or spread terminals, confirm the harness was not tensioned, and check that the moved injector is fully seated with undamaged upper and lower seals. Look for rail debris and compare residual-pressure loss or injector balance if the service procedure provides a safe method.
Also verify the replacement has the correct flow classification or calibration requirement for that engine. If the electrical and installation checks are normal and the same injector again carries the misfire to cylinder 4, the injector itself is the supported conclusion rather than the cylinder wiring or mechanical condition.
24/08/2026 11:22 am
Depressurize the fuel system using the manufacturer’s procedure before opening the rail, keep ignition sources away, and renew any seal specified as single-use. After assembly, prime without starting and inspect every disturbed joint for leakage before running the engine and repeating the misfire-counter test.