SORTING RULES - DIESEL PARTICULATE FILTER (DPF) TROUBLE AND P2002, PULSCAR ANALYSIS OF NHTSA PUBLIC DATA, OCTOBER 2026
License: CC BY 4.0

These are the written rules every complaint was sorted by. They were written, dated and locked before any complaint was sorted; each part carries the UTC date and a checksum of its file, taken before any complaint was sorted under it, so any later change would show.

===== PART 1: THE RULES (locked 2026-10-21T14:01:43Z, checksum fb0825b8b1507a67dfb0161d7500e901ed599e486b43d6c2d829e99b494d4bf8) =====

# Sorting rules - diesel particulate filter (DPF) trouble and P2002 complaints (P2002 study)

Written before any complaint in the set was sorted.

## Pool (how the complaints were found)
NHTSA complaints received 2015-01-01 to 2026-10-04 (782,908 narratives; 2026-10-04 is the latest received date in the
flat files). A complaint is in the pool if its narrative matches any of the following case-insensitive text searches
(rows of electric-car makers Tesla, Fisker, Rivian, Lucid and Polestar that match only the regeneration or soot words are
left out, because there "regen" means regenerative braking):

1. R1 - the DPF efficiency code by any spelling (letter O for zero, a space, hyphen or period after the P, suffix 00):
   P2002 or its bank-2 sister P2003:
   `(?<![A-Z0-9])P\s?[-.]?\s?2\s?[0O]\s?[0O]\s?[23](?:\s?[-:]?\s?[0O]{2})?(?![0-9])`
2. R1c - companion codes of the same filter family (soot load, pressure sensor, regeneration, ash): P244A-P244F, P245x, P246x, P242F, P2BAD, P2BAE, P20EE:
   `(?<![A-Z0-9])P\s?[-.]?\s?(?:244[A-F]|245[0-9A-F]|246[0-9A-F]|242F|2BAD|2BAE|P?20EE)(?![0-9A-Z])`
3. R2 - the filter named in owners' words:
   `particulate|\bdpf\b|d\.p\.f|soot\s+(?:filter|trap)|diesel\s+(?:exhaust\s+)?filter|exhaust\s+(?:gas\s+)?filter|emissions?\s+filter|particle\s+filter|\bfap\b|dpd\b`
4. R3 - regeneration wording (not "regenerative braking"/"regen brake/energy/system") in a narrative that also shows diesel context (diesel, Duramax, Cummins, Power Stroke, TDI, BlueTec, EcoDiesel, CRD, 6.7/6.6/6.4 engine, DEF/AdBlue, DPF):
   `\bregen(?:s|eration|erations|erate|erates|erated|erating)?\b(?![- ]?(?:brak|energy|system))|regenerati(?:on|ng)\s+(?:cycle|process|mode|event)`
5. R4 - the word soot in a narrative that also shows diesel context.

Background for the reader (not a sorting rule): a diesel particulate filter (DPF) is a ceramic filter in the exhaust that
traps soot. When it fills, the engine computer burns the soot off ("regeneration", active or passive; "forced",
"parked" or "stationary" regeneration is one started by a scan tool or a dealer). P2002 is "particulate filter efficiency
below threshold, bank 1" (P2003 is bank 2). Owners say "DPF", "diesel filter", "exhaust filter", "particulate trap",
"regen", "soot". A related part is the diesel oxidation catalyst (DOC) in front of the filter, and the exhaust pressure and
temperature sensors around it. DEF / AdBlue / SCR (the urea system) is a different system.

For each complaint record exactly one CATEGORY and four yes/no FLAGS. You see the whole narrative.

## RELEVANCE
N - Not a diesel particulate filter / regeneration event on THIS vehicle. Use N when:
    - the match is false (the words appear in a list of unrelated parts, a different meaning of "regen", "filter" or "soot");
    - the complaint is only about a GASOLINE particulate filter (GPF) or a gasoline car;
    - the complaint is only about the DEF / AdBlue / SCR (urea) system, a NOx sensor or an SCR code (P20EE alone) with no
      mention of the particulate filter, regeneration, soot or a P2002-family code;
    - the narrative only lists the words among many other complaints with no statement that this vehicle's filter had a
      warning, code, symptom, cleaning, regeneration or repair;
    - the words come from another vehicle, a news story, an advertisement or advice, not this vehicle;
    - the filter is mentioned only as something checked or replaced during a repair for something clearly unrelated.
    NOT N (relevant) when, on this vehicle: a code P2002 / P2003 or a companion code from the pool rules is named; OR the
    particulate filter / regeneration / soot is described as clogged, failed, full, regenerating, blamed, cleaned,
    replaced, diagnosed or suspected by a shop/dealer/mechanic as the cause of a symptom or warning; OR a filter or
    regeneration symptom is described (regen warning, burning smell during regen, high idle, derate for soot) even if the
    cause is unknown.

## CATEGORY (one letter) - what was found or done, on this vehicle
P - Filter replaced. The particulate filter (DPF, or the exhaust/aftertreatment unit that contains it) was named by a
    shop, dealer or mechanic as the cause, was quoted for replacement as the fix, or was replaced (new, remanufactured, used or aftermarket).
C - Cleaned or regenerated only. The filter was cleaned (baked, washed, removed and cleaned), or a forced / stationary / service
    regeneration was run, or the owner cleared it by a long highway drive (the shop or owner says a drive or regeneration fixed it), and no part is named as the cause.
F - Software or campaign only. A reflash / reprogram / software update, recall, TSB, special-coverage or warranty-extension
    procedure was the only repair stated (no part named as cause).
S - Sensor or wiring. A differential-pressure sensor, exhaust-gas-temperature sensor, soot sensor, NOx/oxygen sensor, their
    hoses, harness or connector was named as the cause or was repaired/replaced.
O - Another cause. A repair outside the filter and its sensors was named as the cause (injector, fuel doser, turbo, EGR,
    oxidation catalyst, SCR/DEF part, engine, oil, fuel, driving pattern) or the code or symptom was traced to something else.
K - Checked and cleared. The shop or dealer inspected or tested and found no fault, or only cleared the code, with no
    repair; or the light went out by itself and nothing was done.
U - No diagnosis or repair stated. The event is reported but nothing was found or done yet, or the complaint does not say;
    also an owner's own guess, a forum, a code reader or scan with no shop/dealer/mechanic mentioned.

Precedence when more than one fits: use the FINAL repair the complaint reports as having fixed it (or, if it never got
fixed, the cause the shop named last). A part replaced that the owner says did not help does not count. If several things
were done together and no single one is named, use the most specific named cause in the order P, S, O. Among C, F, K, U:
C before F before K before U. A cause the owner merely guesses at does not count (an owner's "probably the filter"
is U unless a shop or the dealer said it, or the part was replaced by someone).

## FLAGS (yes/no)
derate - the complaint states that because of this fault the vehicle went into limp / reduced power / derate / speed
    limit, lost power, stalled or shut off, or would not start (a countdown to no-start counts).
shorttrip - the complaint (owner or shop) ties the filter trouble to driving pattern: short trips, city or low-speed
    driving, long idling, stop-and-go, towing, or not enough highway driving; or says a long highway drive helped.
recall - the complaint states that a recall, special coverage, service campaign, extension, TSB, software update or "known
    issue" notice for this vehicle was performed, offered, missing, refused, asked about, or is blamed or credited for this event.
returned - the complaint states that after a repair, cleaning or reset the same light, code, regeneration trouble or
    symptom came back, or the repair did not fix it.

## OUTPUT
One CSV line per complaint, in the order given, no header line:
`odino,category,derate,shorttrip,recall,returned,note`
category is one letter (N P C F S O K U); flags are yes or no (for N, all four flags are no);
note is at most 15 words, no commas, saying what decided the category.


===== PART 2: ADDENDUM 1, written before the 52 added complaints were sorted (locked 2026-10-21T14:32:34Z, checksum 11e2d7d7d1e6f3fcbf7815f390359532e59082750288a52ce5458b106f2eeea6) =====

# Addendum 1 to the sorting rules (written before the second batch was sorted)

## Pool, second batch
A completeness check of the whole complaint file found 52 narratives the first searches missed. They are added to the pool and sorted under the same rules above. The wordings that were missed:
- "regen", "regeneration" or a misspelling of it ("REGENARATION", "REGENERTION", "regent system") in a narrative that does not contain any of the diesel words listed in search 4 (mostly Ford F-250/F-350 Super Duty 2015 narratives that say "regen" without saying "diesel");
- Ford's wording "exhaust cleaning" / "drive to clean exhaust" (the message that tells the driver the filter is cleaning itself);
- "PM filter sensor" (particulate-matter filter sensor);
- a few heavy-truck narratives (Freightliner, Peterbilt, Kenworth, Western Star, Hino) that describe a particulate-filter event.
Sixty-two Ford 6.7-litre narratives about an exhaust-gas-temperature sensor shutdown that never name the filter, regeneration or soot were looked at and NOT added (the narrative does not say it is a filter event); they are listed in the published pool history.

Sorting rules for this batch are exactly the rules above (RELEVANCE, CATEGORY, FLAGS, OUTPUT). Rules R1-R12 (part 3 below) apply as written.


===== PART 3: RULES WRITTEN WHILE DISAGREEMENTS WERE SETTLED =====

Where the two independent sortings of a complaint differed on the category or on a flag, the difference was read against the full text and decided under the rules above. Where the rules were silent or ambiguous, a written rule was added; each is applied to every complaint it touches. 76 complaints of the first batch and 12 of the second were settled this way (88 of 618).

R1 (N, incidental mention). If the filter/DPF appears only as a location (shrapnel passed through it, flange before it), in a dealer's list of items for an unrelated failure, as a past replacement under a campaign while the complaint is about another system, as removed/deleted with no warning, code or symptom, or inside a recall text, the complaint is N; "regen" meaning regenerative braking is N. Example 11616275 (also 10715889, 11479478, 10816648).
R2 (N, speculation or denial only). If regen or the filter comes from the owner's guess or denial ("no correlation to the regen cycle", "concerned there was no regen notice") and no filter/regen warning, code, symptom or shop statement is reported, it is N. Example 11654831 (also 10746170).
R3 (derate flag). Yes only when the narrative states limp or reduced power, lost power, stall/shutdown or no-start (a countdown counts) in the reported event; slow acceleration, lag or hesitation alone is no, and a power loss or stall attributed to a separate named failure (turbo blew later, low oil pressure) is no. Example 11254573 (no), 10763196 (yes).
R4 (recall flag). Yes for a recall, TSB, campaign, warranty extension or dealer software update/reflash/reprogram performed, offered, refused, missing for this model, or asked about (including the maker saying "not under recall"), and for a maker or dealer admission of a "known defect". No for the owner's mere opinion that a recall is needed, "no recall issued", community talk, or a recall found for other vehicles. Example 10744953 (yes), 11021663 (no).
R5 (U, cause by owner alone). A cause or part stated only by the owner, with no shop, dealer or mechanic mentioned, is U however firmly worded; also soot blamed for a DEF restriction is relevant, not DEF-only N. Example 11174948 (also 11174452, 11674741, 11110784, 11196671).
R6 (what counts as cause). Count what a shop named as the cause (the last one named if never fixed). A part merely replaced during troubleshooting that the owner says did not help counts for nothing, so with no named cause use the ladder C, F, K, U (a forced regen counts as C even when it failed). Named causes (P, S, O) outrank a procedure such as a regen done in the same visit. Example 11709256 (also 11140049, 11390843, 11505086, 11722490, 11589369).
R7 (pending remedy vs update). A recall, TSB or software revision that is pending, unavailable or refused is not a repair: category U with recall yes. A performed "update", reflash or reprogram of a module with no part replaced is F with recall yes. Example 11767670 (U), 11322697 (F).
R8 (K vs U). Dealer or shop inspected and could not find, duplicate or determine the cause, said it is normal, or only cleared the code, with no repair: K. U if the work is still in progress, parts are being replaced unspecified, or no shop visit is stated. Example 11254428 (K), 11537580 (U).
R9 (returned flag). Yes when, after a repair, reset or cleaning, the same warning, code or symptom came back or persists despite stated shop visits, or the repair set that included the filter failed again; no when only a different new failure follows or no repair is stated. Example 11568669 (yes), 11764379 (no).
R10 (driving pattern as cause). A dealer or shop attributing the clogged filter to short-distance use and advising a long drive, with no regen done, is O (driving pattern) with shorttrip yes; C is only when a drive or regen was actually done and cleared it. Example 11601215.
R11 (sensor list). S covers differential-pressure, exhaust-temperature (and its control module), soot/PM and NOx/oxygen sensors with their wiring; a MAF sensor or an exhaust valve is not on the list, so O. Example 11664846 (O), 11706824 (S).
R12 (P by dealer naming). A dealer or shop that names the filter as clogged, failed or needing replacement, lists it among parts to replace, or charges for its repair (method unstated) gives P (P outranks S and O when listed together). Example 10744484 (also 10746726, 10849614, 11760557).


Decisions in the second batch (52 complaints added by the completeness check) were made under the same rules; the main ones applied were R3 (what counts as a loss of power), R5 (a cause stated only by the owner is category U), R6 (a part replaced that did not help counts for nothing), R8 (a shop that could not find or duplicate the fault is K) and R10 (a shop that blames short use is O with the short-trip flag). One reading was added for a complaint cut off mid-word ("having the DPF r"), which was sorted U: the repair is not stated.

===== PART 4: POOL HISTORY =====

First search (566 complaints): the searches R1 to R4 in part 1. Rows of electric-car makers that matched only the regeneration or soot words (18) were left out. A wider search by symptom (a diesel vehicle with exhaust or emissions wording and a power or warning word) was tried and rejected before sorting: 450 narratives, almost all about the urea (DEF/SCR) system, a fuel pump or an exhaust leak, none naming the filter.
Second search (52 complaints): a completeness check of the whole file with other spellings and phrasings (part 2). 62 Ford 6.7L narratives about an exhaust-gas-temperature sensor shutdown that never name the filter, regeneration or soot were looked at and not added.
Total 618; 405 relevant on the owner's vehicle, 213 not.