John Loper II
4e52c91c9b
Diagnosis: Removing forward O2 sensors immediately restored full power. Test proved the catalytic converters are severely restricted. Updated: - README.md: Added confirmed diagnosis section - progress.md: Marked diagnosis complete, updated next steps
1.3 KiB
1.3 KiB
RPMLimitPowerIssue - Progress Tracker
Current Status
✅ DIAGNOSIS COMPLETE - Clogged catalytic converters confirmed
Completed
- Initial project setup
- Created project documentation structure
- Documented symptoms and known work
- Identified 7 potential causes
- Confirmed diagnosis: Removed forward O2 sensors → full power returned immediately
Next Steps
- Order replacement catalytic converters (primary fix)
- Reinstall O2 sensors after cat replacement
- Test drive to verify full power restored
- Consider O2 sensor replacements if old/damaged
Diagnosis Details
Test performed: Removed forward O2 sensors (located upstream of catalytic converters) Result: Power immediately returned, RPMs no longer limited at 3000 Conclusion: The catalytic converters are severely restricted/clogged. When the O2 sensors were removed, they created enough clearance for exhaust to flow freely, bypassing the restriction.
Notes
- TPS already replaced with no improvement
- Spark plugs already replaced with no improvement
- This was NOT a fuel, air, or ignition issue - purely exhaust restriction
- The forward O2 sensors are embedded in the exhaust stream and were blocking the flow when clogged cats were present
Last Updated: 2026-03-29 18:48 EDT