{"model": "openai/gpt-oss-20b", "provider": "Groq API (free tier)", "task": "auto-diag", "prompt": "Write a step-by-step diagnostic walkthrough for high school automotive students: a 2012-2018 gasoline car comes in with a check engine light and code P0300 (random/multiple cylinder misfire). Show the logical order of tests from simplest to most involved, what tools are needed, what each result means, and safety notes. Format it as a student handout.", "system": "You are helping a high school career and technical education (CTE) teacher. Produce classroom-ready material.", "temperature": 0.3, "ran_at": "2026-10-16T05:21:25-0700", "output": "# Diagnostic Walk\u2011Through  \n**P0300 \u2013 Random/Multi\u2011Cylinder Misfire**  \n*2012\u20112018 Gasoline Passenger Car*  \n\n> **Goal:** Identify the cause of the random misfire and eliminate the P0300 code.  \n> **Audience:** High\u2011school automotive students (CTE).  \n> **Format:** Classroom\u2011ready handout \u2013 step\u2011by\u2011step, tools, safety, and interpretation.\n\n---\n\n## 1. Safety First  \n| Safety Tip | Why It Matters |\n|------------|----------------|\n| **Wear gloves & safety glasses** | Protect hands from hot surfaces & debris; protect eyes from spark or fuel spray. |\n| **Disconnect the battery** | Prevent accidental short circuits while working on ignition or fuel system. |\n| **Let the engine cool** | Avoid burns from hot engine components. |\n| **Work on a flat, stable surface** | Prevent wheel or body movement that could cause injury. |\n| **Keep the work area dry** | Prevent slips and electrical hazards. |\n\n---\n\n## 2. Tools & Equipment Checklist  \n\n| Tool | Purpose | Notes |\n|------|---------|-------|\n| OBD\u2011II scan tool (with live data) | Read & clear codes, monitor misfire counts | Must support live RPM, misfire, and sensor data |\n| Spark plug socket set (incl. torque wrench) | Remove/inspect spark plugs | Use correct size for the engine |\n| Compression gauge | Test cylinder compression | Calibrate before use |\n| Fuel pressure gauge (with adapter) | Check fuel pressure | Use correct fuel rail gauge |\n| Vacuum gauge | Detect vacuum leaks | Attach to intake manifold or vacuum port |\n| Multimeter (DC & AC) | Test coil resistance, voltage | Set to correct range |\n| Torque wrench | Tighten coils & plugs to spec | Follow manufacturer torque specs |\n| Screwdrivers, pliers, socket set | General removal & inspection | Keep organized |\n| Clean rags & solvent (acetone) | Clean spark plug wells & coil boots | Avoid contamination |\n| Engine coolant temperature gauge | Verify sensor operation | Optional but useful |\n\n---\n\n## 3. Step\u2011by\u2011Step Diagnostic Flow  \n\n> **Start with the simplest checks and progress to more involved tests.**  \n> **Record every result** (e.g., \u201cSpark plugs: 0.8\u202fmm gap, black fouling\u201d) for later comparison.\n\n### Step 1 \u2013 Verify the Code & Check for Other Codes  \n1. **Connect scan tool** \u2192 Read codes.  \n2. **Clear codes** \u2192 Restart engine, see if P0300 re\u2011appears.  \n3. **Check live data** \u2192 Look for misfire counts per cylinder, RPM, throttle position.  \n\n> **Interpretation**  \n> \u2022 If P0300 clears and does not return \u2192 likely a transient issue (e.g., loose connector).  \n> \u2022 If P0300 returns immediately \u2192 proceed to Step 2.\n\n---\n\n### Step 2 \u2013 Inspect Spark Plugs & Wires/Coils  \n1. **Remove all spark plugs** (use socket & torque wrench).  \n2. **Inspect plugs**:  \n   - **Color**: Black = fouled (fuel/air), white = oil, green = coolant.  \n   - **Gap**: Measure with feeler gauge.  \n3. **Check ignition coils** (or coil packs):  \n   - **Visual**: Look for cracks, burnt marks, or oil contamination.  \n   - **Resistance test** (multimeter) \u2192 compare to spec.  \n\n> **Interpretation**  \n> \u2022 **Fouled plugs** \u2192 Misfire due to poor combustion. Replace plugs, re\u2011gap.  \n> \u2022 **Damaged coils** \u2192 Replace coil(s).  \n> \u2022 **Good plugs & coils** \u2192 Move to Step 3.\n\n---\n\n### Step 3 \u2013 Check Fuel System (Pressure & Delivery)  \n1. **Connect fuel pressure gauge** to the fuel rail (use proper adapter).  \n2. **Start engine** \u2192 Read pressure.  \n3. **Compare to manufacturer spec** (usually 30\u201350\u202fpsi for gasoline engines).  \n\n> **Interpretation**  \n> \u2022 **Low pressure** \u2192 Fuel pump, filter, or regulator issue.  \n> \u2022 **High pressure** \u2192 Possible injector leak or regulator fault.  \n> \u2022 **Normal pressure** \u2192 Proceed to Step 4.\n\n---\n\n### Step 4 \u2013 Inspect for Vacuum Leaks  \n1. **Attach vacuum gauge** to a vacuum port on the intake manifold.  \n2. **Start engine** \u2192 Observe reading.  \n3. **Look for sudden drops** when throttle is opened or closed.  \n\n> **Interpretation**  \n> \u2022 **Drop in vacuum** \u2192 Leak in intake manifold, vacuum hose, or PCV system.  \n> \u2022 **Stable vacuum** \u2192 Move to Step 5.\n\n---\n\n### Step 5 \u2013 Compression Test  \n1. **Remove spark plugs** (if not already).  \n2. **Insert compression gauge** into each cylinder.  \n3. **Crank engine** (3\u20135 turns) \u2192 Record compression reading.  \n\n> **Interpretation**  \n> \u2022 **Compression < 70\u202fpsi** (or < 50\u202f% of max) \u2192 Mechanical issue (piston, valve, head gasket).  \n> \u2022 **Compression within spec** \u2192 Proceed to Step 6.\n\n---\n\n### Step 6 \u2013 Check Engine Sensors  \n| Sensor | What to Check | Why It Matters |\n|--------|---------------|----------------|\n| **Engine Coolant Temperature (ECT)** | Read live data \u2192 Should be ~90\u202f\u00b0C at idle. | Misfire can occur if engine runs too hot or too cold. |\n| **Mass Air Flow (MAF)** | Check for dirty filter, sensor reading. | Incorrect air measurement \u2192 Rich/lean mixture. |\n| **Throttle Position Sensor (TPS)** | Verify smooth operation, no jumps. | Erratic throttle can cause misfire. |\n| **Crankshaft Position Sensor** | Check voltage output. | Faulty sensor \u2192 Engine timing issues. |\n\n> **Interpretation**  \n> \u2022 **Sensor out of spec** \u2192 Replace or clean.  \n> \u2022 **All sensors OK** \u2192 Move to Step 7.\n\n---\n\n### Step 7 \u2013 Inspect Ignition Timing & Wiring  \n1. **Check ignition timing** (if equipped with a timing light).  \n2. **Inspect wiring harnesses** for frayed or corroded connectors.  \n\n> **Interpretation**  \n> \u2022 **Timing off** \u2192 Adjust or replace timing components.  \n> \u2022 **Damaged wiring** \u2192 Repair or replace.\n\n---\n\n### Step 8 \u2013 Final Test & Re\u2011Scan  \n1. **Re\u2011install all components** (spark plugs, coils, hoses).  \n2. **Reconnect battery**.  \n3. **Start engine** \u2192 Observe for smooth idle, no hesitation.  \n4. **Run scan tool** \u2192 Verify P0300 cleared and no new codes.  \n\n> **If P0300 returns** \u2192 Re\u2011visit the step where the result was abnormal.  \n> **If P0300 remains cleared** \u2192 Problem solved.\n\n---\n\n## 4. Quick Reference Cheat Sheet  \n\n| Symptom | Likely Cause | Quick Test | Result Indicates |\n|---------|--------------|------------|------------------|\n| **Black fouled plugs** | Rich mixture, fuel leak | Inspect plugs | Replace plugs |\n| **Coil resistance out of spec** | Coil failure | Multimeter | Replace coil |\n| **Low fuel pressure** | Pump/filter/regulator | Fuel gauge | Repair fuel system |\n| **Vacuum drop** | Intake leak | Vacuum gauge | Repair leak |\n| **Low compression** | Valve/piston/gasket | Compression gauge | Mechanical repair |\n| **Sensor out of spec** | Faulty sensor | Live data | Replace sensor |\n| **Timing off** | Timing belt/chain issue | Timing light | Adjust/replace timing |\n\n---\n\n## 5. Safety Reminders (Quick Check)  \n\n- **Battery disconnected** before working on ignition or fuel system.  \n- **Engine cool** before touching spark plugs or valves.  \n- **Wear gloves** when handling fuel or cleaning components.  \n- **Keep tools organized** to avoid tripping hazards.  \n- **Dispose of used solvents** properly.  \n\n---\n\n## 6. Summary  \n\n1. **Read & clear codes** \u2192 Verify persistence.  \n2. **Inspect spark plugs & coils** \u2192 Replace if needed.  \n3. **Check fuel pressure** \u2192 Ensure proper delivery.  \n4. **Look for vacuum leaks** \u2192 Seal any found.  \n5. **Test compression** \u2192 Identify mechanical faults.  \n6. **Verify sensors** \u2192 Replace or clean.  \n7. **Check timing & wiring** \u2192 Correct any issues.  \n8. **Re\u2011test** \u2192 Confirm P0300 cleared.\n\n> **Remember:** P0300 is a *symptom* of a misfire. The root cause can be electrical, fuel, mechanical, or sensor\u2011related. Follow the logical order above to isolate the problem efficiently.  \n\nGood luck, and happy diagnosing!", "finish_reason": "stop", "usage": {"queue_time": 0.09258228, "prompt_tokens": 171, "prompt_time": 0.008311847, "completion_tokens": 2336, "completion_time": 2.52928663, "total_tokens": 2507, "total_time": 2.537598477, "completion_tokens_details": {"reasoning_tokens": 446}}}