Bob's Mechanical Repairs

P2459 — Diesel Particulate Filter Regeneration Frequency

Bob's Mechanical Repairs — independent family-run garage in Birnam, Dunkeld, Perthshire. Call 01350 727 276 or email [email protected].

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The car is regenerating far more often than it should. That is a symptom, not a fault in itself — something is making excess soot or interrupting the cycle.

P2459 — also written P2459, P 2459, 2459 — is the OBD-II code for diesel particulate filter regeneration frequency. Same code, same fix: this page covers every spelling of it.

P2459 is a emissions fault code, typically costing £120–£1400 to put right in a UK garage.

What causes P2459?

  • Repeated short journeys interrupting regeneration
  • Leaking or worn injectors making excess soot
  • EGR stuck open
  • Turbo seal leaking oil into the exhaust
  • Poor quality fuel

How P2459 is fixed

  • Injector back-leak test
  • Check EGR operation on live data
  • Inspect the turbo for oil leakage
  • Change driving pattern to include regular longer runs

P2459 repair cost in the UK

Most P2459 repairs land between £120–£1400 including parts and labour. The spread is wide because the cheap fix (a sensor, a hose, a leak) and the expensive fix (a major component) throw the same code — which is why a proper diagnosis before parts are bought saves the most money.

Can you drive with P2459?

Yes, but frequent regeneration dilutes engine oil with diesel — check the oil level and change it early.

Urgency: medium.

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