Hey all — long-time flat-six guy, occasional DIY wrencher. I built a free, open-source garage app for Porsches (started on the
981
, then added
987.1
/
987.2
), and I'm now starting work on
911
support, kicking off with the 991. Posting here because I don't have anywhere near the reference depth for the 991 yet that I've built up for the
981
/987, and I'm hoping this crowd can help fill the gaps.
The 991 is already up, but still unverified fully yet
What it does (already live for 981/987):
Service history
— log every job with structured line items (part numbers, costs, mileage, notes). Not a text dump; you can actually search and reuse it later.
Service planning
— build upcoming jobs with linked how-to references, tick items off as you go, and start a service record directly from a plan when you're done.
OEM parts catalog
— thousands of parts parsed from the official Porsche PET catalog, searchable by part number or description.
Fault finding
— SAE J2012 + Porsche-specific OBD codes, symptom search, and a curated list of known generation-specific issues with severity ratings (IMS/bore scoring territory on early 987s, AOS and coolant pipes on the 981, etc.).
Deep model knowledge
— the app has an extensive, generation-specific knowledge base under the hood that powers fault finding and the AI assistant — ask it a question about your car and it actually knows the platform, not just generic OBD definitions.
Live OBD
— connect a compatible adapter and pull live sensor data and fault codes straight from the car, not just static lookups.
Desktop apps for Mac and Windows
— for folks who want to plug an OBD adapter straight into a laptop in the garage rather than juggling a phone and a dongle.
3D exterior + X-ray
— orbit a real 3D model in your car's color, strip it down to every major system (engine, brakes, cooling, fuel, wiring), each part tied to numbers, torque, and intervals for your generation.
AI assistant (optional)
— if you use Claude, ChatGPT, or Gemini, there's an MCP integration that can read your garage, look up specs/faults/parts, and log service records from natural language, with your approval each time. Totally optional; the app works fine without it.
Now starting on the 911 (991):
same architecture, same feature set — I just need reference material to build out the generation-specific knowledge base and fault-finding data properly for the platform. I already have a service manual, but If anyone can point me to or share factory workshop manuals, wiring diagrams, PET/parts catalog data, SIT yearbooks, training materials, or TSBs for the 991, I'd genuinely appreciate it — it makes a real difference in how accurate and useful the tool ends up being.
The usual disclaimers: hobby project, not affiliated with Porsche AG. Reference data only - always verify torque, intervals, and procedures against the official manual before turning a wrench. Completely free, no ads, no subscriptions. Source is on GitHub if you want to poke around or run it locally.
Links:
Site:
Free Boxster & Cayman garage · FLAT·SIX
GitHub:
GitHub - dmitry-grechko/flat-six
Would genuinely appreciate feedback from this crowd too, and happy to take feature ideas / bug reports here or on GitHub as 911 support comes together.
Some screenshots
Hi
@grechkoda
,
This looks like a very exciting project based on what you have done for the 987/981 platform. I own a 991.1 that I do a fair amount of wrenching on and have compiled a decent amount of information over time. I would be glad to share those documents with you. I have a full parts catalog, a factory workshop service repair manual, firmware for the PCM unit, and maintenance checklists. If you have the need for any of that, let me know what is the best way to share those with you and I will send them your way.
Victor O.
It looks like a lot of work went into this. Very impressive. I hope you are able to include
718
at some point. It looks great thus far. Keep up the good work!
Thank you! Yes, it is in works, will be adding soon
