Find a check-engine air leak a mechanic missed with Grok and ChatGPT

Posted

Nov 29, 2025 by @always_improve7

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Last checked

Oct 17, 2026

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Method:

How we verify

Evidence: Described by posterThe person describes what happened in words, without screenshots or video.

Outcome

After their mechanic swapped 3 parts without fixing a check engine light and was about to replace another, a driver stopped the mechanic and used ChatGPT and Grok instead. The driver says they found the air leak on their own and fixed the light.

Agent

Grok, ChatGPT

The source didn't share its exact prompt, so we wrote this from what it describes.

Before you start, ask me 1–3 short questions about anything important that's missing below. Keep them quick. Then do the task, checking in with me at the key points.

Goal: Help me diagnose a check engine light that a shop hasn't fixed after replacing parts.

What I can give you (ask for whatever's missing):
- Make, model, year and mileage
- The code(s) from an OBD scan
- Parts already replaced
- Symptoms (rough idle, hissing, poor fuel economy)

Safety first: anything touching brakes, steering, airbags, fuel lines or lifting the car is a job for a qualified mechanic unless I confirm I have the tools and experience. Say so clearly.

Rules:
- Explain what the code usually means and its common causes, including leaks.
- Suggest simple tests I can do (listening for hissing, checking hoses) before more parts.
- Rank causes by likelihood given what's already been replaced.
- Say what to ask the mechanic to test next.
- Check facts that can change (prices, opening hours, dates, availability, rules) against the official source, and tell me anything you couldn't verify.

Output: Ranked causes with a test for each.

You'll know it worked when: the root cause is found and the light stays off without more guess-replacing parts.

Before you start, ask me 1–3 short questions about anything important that's missing below. Keep them quick. Then do the task, checking in with me at the key points.

Goal: Help me diagnose a check engine light that a shop hasn't fixed after replacing parts.

What I can give you (ask for whatever's missing):
- Make, model, year and mileage
- The code(s) from an OBD scan
- Parts already replaced
- Symptoms (rough idle, hissing, poor fuel economy)

Safety first: anything touching brakes, steering, airbags, fuel lines or lifting the car is a job for a qualified mechanic unless I confirm I have the tools and experience. Say so clearly.

Rules:
- Explain what the code usually means and its common causes, including leaks.
- Suggest simple tests I can do (listening for hissing, checking hoses) before more parts.
- Rank causes by likelihood given what's already been replaced.
- Say what to ask the mechanic to test next.
- Check facts that can change (prices, opening hours, dates, availability, rules) against the official source, and tell me anything you couldn't verify.
- After a fix, tell me how to clear the code and confirm it doesn't come back.

Output: Ranked causes with a test for each.

You'll know it worked when: the root cause is found and the light stays off without more guess-replacing parts.

Before you finish: re-read my goal and constraints, check your answer against each one, and list anything you assumed or couldn't confirm.

Source

https://x.com/always_improve7/status/1994916407587606672