My Jeep’s money light lit up — the dreaded check engine light.
Step 1: Scanning the code
I hooked up my OBD2 scanner and it came back with Code P1128: Closed Loop Fueling Not Achieved – Bank 1.
📸 Gallery: Code Screenshots
This is the code reader I used:
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Step 2: What P1128 means
When you see P1128 (Closed Loop Fueling Not Achieved – Bank 1), it usually points to:
- A loose or faulty gas cap
- An O₂ sensor going bad
- A small EVAP system leak
- Less commonly, fueling/air issues
I started mapping out a Saturday troubleshooting plan:
- Check the gas cap seal and snugness
- Inspect for small vacuum leaks
- Test O₂ sensor function
- Consider fuel pressure issues if problems persist
I even had an O₂ sensor lined up:
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Step 3: The gas cap twist
But here’s the funny part. While running errands, I hopped out and gave the gas cap three solid turns.
The check engine light went off immediately. 💡
If your cap is cracked or the seal is worn, a replacement can save you headaches:
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Or add a rugged cover for extra style + protection:
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Wrapping up
I’m glad it turned out to be simple, and hopefully this post helps other Jeep owners searching for P1128 Closed Loop Fueling Not Achieved – Bank 1.
Sometimes the “money light” is just a reminder to give your gas cap a twist.
– Jake 🚙💨
