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Ubify Core Engineering Team
SOFTWARE ENGINEERS & SYSTEMS ARCHITECTS
About This Tool
When your vehicle's Check Engine light illuminates, the ECU stores standardized 5-character Diagnostic Trouble Codes alongside freeze-frame operating telemetry. This tool decodes the subsystem, evaluates combined fuel trims (STFT + LTFT), and diagnoses whether faults stem from intake vacuum leaks, failing O2 sensors, or catalytic converter degradation.
How to Use
- 1
Enter any 5-digit OBD-II code (e.g. P0171, P0300, P0420, U0100).
- 2
Enter freeze-frame Short Term and Long Term Fuel Trim percentages.
- 3
Review automated diagnostic findings differentiating vacuum leaks from fuel pump failure.
- 4
Follow the step-by-step DIY diagnostic checklist before taking your car to a mechanic.
Frequently Asked Questions
What do the letters P, C, B, and U mean in OBD2 codes?
P stands for Powertrain (engine and transmission), C stands for Chassis (brakes, steering, suspension, ABS), B stands for Body (airbags, climate control, lighting), and U stands for Network (CAN Bus module communication).
How do fuel trims identify a vacuum leak?
If fuel trims (STFT + LTFT) are high positive (e.g. +20%) at idle but drop down to normal (+2% to +5%) when engine RPM is raised to 2,500 RPM, it confirms a vacuum leak because unmetered air enters less proportionally at higher throttle openings.