Drivable short-term, but fix now to avoid damage.
This code means the engine computer detected high voltage or an open circuit on the cylinder 1 fuel injector control, so that injector may not be firing correctly. It typically points to an open wire, a short to power, a corroded connector, or a failed injector. Fixing it usually starts with inspecting the wiring and connector, then testing or replacing the injector if needed.
$150 – $600
Varies by vehicle and root cause.
Short trips are usually okay, but it's best to limit driving. The misfire it often causes on cylinder 1 can damage the catalytic converter over time. Have it diagnosed soon, and if the engine shakes badly or loses a lot of power, avoid driving until it's repaired.
Wiring or connector repairs may cost $150 to $300, while replacing the cylinder 1 injector usually runs around $300 to $600 with labor. A proper diagnosis confirms whether it's the circuit or the injector before parts are replaced.
It's moderately to fairly serious because a misfiring cylinder hurts drivability and can damage the catalytic converter. It won't usually strand you right away, but ignoring it risks a much larger repair. Address it promptly.
Both are cylinder 1 injector circuit codes, but P0263 is 'High' (too much voltage or an open circuit) while P0262 is 'Low' (a short to ground). The direction of the fault helps a technician focus the wiring and injector tests. The repairs and parts are otherwise similar.