Cylinder 8 Fuel Trim at Min Limit
The P02B7 code indicates that the fuel trim for cylinder 8 has reached its minimum limit, meaning the engine control module (ECM) is detecting an overly rich condition on that cylinder and has reduced fuel delivery as much as possible. This can be caused by a stuck-open fuel injector, a faulty oxygen sensor, or a mechanical issue like low compression. If left unaddressed, it can lead to catalytic converter damage and poor engine performance.
01. Most Common Causes
- Stuck open fuel injector on cylinder 8
- Faulty oxygen sensor (pre-cat)
- Engine mechanical issue (low compression, valve problem)
02. Symptoms You Will Notice
- Check Engine Light on
- Rough idle or misfire on cylinder 8
- Poor fuel economy
03. Step-by-Step Diagnosis
Step 1: Scan for additional codes and check freeze frame data.
Step 2: Inspect fuel injector on cylinder 8 for leakage or sticking.
Step 3: Test oxygen sensor readings and compare bank 1 vs bank 2.
Step 4: Perform a compression test on cylinder 8.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as it can damage the catalytic converter and cause further engine issues.
How much does it cost to fix?▼
Repair costs typically range from $150 to $400 depending on the cause, with injector replacement being the most common fix.