Detonation/Spark Knock: Sensor/System
Check for the following conditions that may cause the engine to run lean:
- Any water intrusion in the HO2S connector.
- An exhaust leak between the HO2S and the engine. Go to EXHAUST LEAKAGE .
- Any vacuum leaks.
- Incorrect fuel pressure. Go to FUEL PRESSURE TEST under FUEL SYSTEMS (GASOLINE) in BASIC DIAGNOSTIC PROCEDURES - 2.2L ALERO, CAVALIER, GRAND AM & SUNFIRE article.
- Any restricted fuel injectors.
- Fuel contamination.
- Any vacuum hoses that are split, kinked, or improperly connected.
Check for an Engine Coolant Temperature (ECT) sensor that has shifted in value. Go to TEMPERATURE VS. RESISTANCE table.
TEMPERATURE VS. RESISTANCE
| °F (°C) | Ohms |
|---|---|
| 302 (150) | 47 |
| 284 (140) | 60 |
| 266 (130) | 77 |
| 248 (120) | 100 |
| 230 (110) | 132 |
| 212 (100) | 177 |
| 194 (90) | 241 |
| 176 (80) | 332 |
| 158 (70) | 467 |
| 140 (60) | 667 |
| 122 (50) | 973 |
| 113 (45) | 1188 |
| 104 (40) | 1459 |
| 95 (35) | 1802 |
| 86 (30) | 2238 |
| 77 (25) | 2796 |
| 68 (20) | 3520 |
| 59 (15) | 4450 |
| 50 (10) | 5670 |
| 41 (5) | 7280 |
| 32 (0) | 9420 |
| 23 (-5) | 12,300 |
| 14 (-10) | 16,180 |
| 5 (-15) | 21,450 |
| -4 (-20) | 28,680 |
| -22 (-30) | 52,700 |
| -40 (-40) | 100,700 |