You have a DPF fault, maybe a quote for a new filter, and one question: is that really the fix? Send me every stored code, the six numbers from the free sheet, and the quote. Within 48 hours you get a written reply, dated, that you can take to the garage.
Reply within 48 hours. One car, one fault, one reply, plus one follow-up. Refund if I cannot give you a useful answer from what you send.
What the reply covers
- Does the diagnosis fit your numbers. Soot calculated against measured, ash against its limit, pressure at idle and engine off. If it is not the DPF at all, I say so.
- What the quote leaves out. The cause, the readings, the guarantee, the “what if it comes back” line.
- What the parts should cost. Dated prices for your part number from the big retailers, genuine and aftermarket, so you can see the mark-up.
- How to check the labour where you live. Hours times rate, and where to get a second labour quote in your country in ten minutes.
- Which route applies. Warranty, extended warranty, consumer-rights or ombudsman routes that exist for your case, and what they need from you before any work is done.
What it is not
I am not a mechanic. I test on my own cars, and I read DPF fault-code cases every day for this site. This is a second pair of eyes on your numbers from someone who has no reason to sell you a filter, not an inspection, and the garage still makes the final call. If your case needs a physical inspection, I say that too, and refund you.
How it works
- Pay $19. The receipt email links to the form.
- Fill in the form. Five minutes. Every stored code, the six numbers (or “refused” where the garage would not give one), the quote, and a photo if you have it.
- Read the reply within 48 hours. Six short sections (below). Take it to the garage, or to a second garage.
- One follow-up. If the garage comes back with new numbers or a new price, reply with them.
What a reply looks like
A sample, with the numbers changed. Every reply follows these six headings.
DPF quote check: Skoda Octavia 2.0 TDI (2016), 96,000 miles. 30 September 2026.
1. What you sent. Codes P2463 and P0401 stored. Soot calculated 38 g, soot measured 9 g. Ash 62 g, limit 80 g. Pressure 31 mbar at hot idle, 0 mbar engine off. Quote from a main dealer: new DPF, £2,780 fitted, “filter blocked”.
2. What the numbers say. Calculated soot is high but measured soot is low, so the pressure sensor is not seeing a full filter. Ash at 62 of 80 g means the filter has life left. A P0401 (EGR flow) stored alongside means the car has not been able to regenerate; the soot built up behind that fault.
3. Does the diagnosis and repair fit. Not on these numbers. The quote treats the filter as the cause. The readings point to the EGR fault as the cause and the soot as the result. A filter alone would clog again.
4. What the quote leaves out. No cause named. No readings on the quote. No guarantee period stated. No mention of the EGR code.
5. Parts prices and the labour check. Genuine filter for this part number: £1,640 to £1,890 plus VAT at the usual retailers this week; aftermarket £320 to £610. Book time for a filter swap on this engine is about 2.5 hours; at a dealer rate of £160 an hour that is £400, so the quote’s labour share is around £700 and worth asking about. For a second labour figure in the UK: two independent quotes through a booking site take ten minutes.
6. Your route, and what to say. Car is out of warranty. Ask the dealer, in writing: “The scan shows P0401 with the DPF codes. Does this quote fix the EGR fault, and what are the soot and ash readings you based the new filter on?” If they will not answer, get an independent to fix the EGR fault and run a forced regeneration (soot is under 45 g). Expected cost of that route: £250 to £500. Keep this reply and the dealer’s quote together; they are your record if it comes back.
I am not a mechanic. This is a second pair of eyes on your numbers, not an inspection; the garage makes the final call.
Questions
What if the garage will not give me the readings? Send the form with “refused” in those boxes. The reply covers what the refusal means and what to ask for next, and a route that does not depend on that garage.
What if it is not a VW group car? The numbers mean the same on any diesel with a DPF. Ash limits and part prices differ; I look them up for your car.
What if it turns out not to be the DPF? That is a good outcome. The reply says what the codes point to instead, and what to do first.
How do I pay? Card or PayPal through Payhip. Price in US dollars; your bank converts.
Do you get anything from garages or parts sellers? No. There are no partner links in a reply, and no garage pays me.
Refunds? If I cannot give you a useful answer from what you send, the $19 goes back the same way it came. No refunds after the reply is sent; the reply is the product.
Ayush Sondhi, thecarlane.com. Not a mechanic. Not affiliated with any manufacturer, dealer or garage. Prices quoted in replies are dated retail listings on the day of writing and change.