A customer came in last month. DPF light on. Engine in limp mode. Another workshop had already quoted $4,200 for a replacement filter.
We tested it first.
Flow reading: 68% of factory spec. Blocked? Yes. Uncleanable? Absolutely not.
Clean and regen cycle: $590. Drives perfectly. Still driving perfectly.
Why We Always Test First
A DPF light tells you the filter is partially blocked. It doesn't tell you how blocked. It doesn't tell you whether it's cleanable. It doesn't tell you whether the underlying problem is the DPF or something else causing it to block faster than normal.
That's what a diagnostic is for.
We measure flow through the filter before we recommend anything. We check the regen cycle is actually firing correctly. We look at what's causing the blockage — because if you clean the filter without fixing the cause, you'll be back in three months with the same problem.
What "Testing" Actually Looks Like
- Flow measurement through the DPF (before and after)
- Soot load reading via diagnostic scanner
- Check of the regen system — is it triggering, completing, or failing partway through?
- Inspection of upstream components — turbo, injectors, EGR — anything that contributes to excessive soot
Takes time but it's worth it.
The Bottom Line
DPF replacement is sometimes necessary. But you won't know until you've tested it properly. Don't let anyone talk you into a replacement without a diagnostic first.
That's how we do it. That's how it should be done.
Book a DPF diagnostic: call us on 08 8952 4895 or stop in at the workshop.
