OBD2 scanners, fault code interpretation, and DIY repair guides. I diagnose cars the same way I diagnose network issues — methodically.
Look it up in our OBD2 code database — 200+ codes with causes, symptoms, and fix procedures.
Systematic checks for weak car air conditioning before you connect manifold gauges or buy refrigerant, including fuses, clutches, and condenser fans.
How to measure primary and secondary resistance on a coil-on-plug or distributor coil, what the spec ranges look like, and when resistance lies to you.
A step-by-step procedure for finding a parasitic draw with a multimeter. How to settle the modules, set the meter, and pull fuses to isolate the circuit.
P0340 means no signal from the camshaft position sensor. Learn what causes it, how to diagnose it, and whether you can fix it yourself.
P0455 means a large EVAP system leak was detected. Learn the most common causes, how to find the leak, and what repairs to expect.
Subaru uses manufacturer-specific codes cheap scanners miss. Comparison of the best OBD2 scanners for Subaru: Foxwell, BlueDriver, Autel, iCarsoft.
P0420 doesn't always mean a dead cat. Rule out exhaust leaks, O2 sensors, and running conditions before spending $1,200 on a converter.
Read OBD2 codes with your phone using a Bluetooth adapter and free app. What works, what doesn't, and the adapter trap to avoid on iPhone.
P0171 means more air than fuel on Bank 1. Use LTFT live data, smoke test, and MAF cleaning before touching anything else.
The P1604 code means Startability Malfunction — often caused by a weak battery. Here's what's actually happening, how to diagnose it, and the correct fix.
Know whether your engine has a belt or chain, what the replacement intervals are, and what a skipped service actually costs you.
P0442 means a small EVAP leak detected. Here is what the system does, why the code comes back, and how to find and fix the actual leak.
Codes tell you where to look. Live data tells you what is actually happening. Learn the key PIDs, normal ranges, and how to read fuel trims correctly.
P0128 almost always means a stuck-open thermostat, not a bad sensor. Learn how to confirm it with live data and why ignoring it costs you fuel and heat.
TPMS light on after a rotation? Learn how direct and indirect systems work and the right reset method for your vehicle before you make it worse.
P0401 means insufficient EGR flow, not no flow. Here's how to test the valve, find the real cause, and avoid the mistake that makes it come back.
Learn what OBD2 readiness monitors are, why they reset after a repair, and how to complete a drive cycle before your emissions test.
P0300 means the ECM cannot pin the misfire on one cylinder. Here is how to isolate the cause using live data, swap tests, and compression checks.
Resting voltage, cranking drop, charging voltage at idle and 2000 RPM — here is every test you need to diagnose a battery or alternator problem.
Steady CEL vs flashing CEL changes everything. Here is how to triage a check engine light, get a free scan, and decide if you can keep driving.
