Engine Repair Nashville TN — ProTech Auto Repair

Common Codes

What Are Those Codes Telling You?

When your check engine light comes on, your vehicle's computer stores a diagnostic trouble code (DTC). We scan it free and explain exactly what it means before any work begins.

P0300 Series

Random / Multiple Cylinder Misfire

Usually means spark plugs, ignition coils, or fuel injectors need attention. Left untreated, misfires damage catalytic converters — an expensive fix.

P0171 / P0174

System Too Lean (Bank 1/2)

Often caused by a vacuum leak, dirty MAF sensor, or failing O2 sensor. Can reduce fuel economy and cause rough idle.

P0420 / P0430

Catalyst System Efficiency Below Threshold

Indicates a failing catalytic converter — or sometimes just an O2 sensor issue. We run live data tests to confirm before recommending replacement.

P0440 Series

Evaporative Emission Control (EVAP)

Often triggered by a loose gas cap — or a faulty purge valve or EVAP canister. We test the entire system before replacing anything.

Our Process

From Check Engine Light to Road-Ready

1

Free OBD-II Diagnostic Scan

We connect our factory-grade scanner and pull all stored codes. We also run live data streams to see exactly what the engine is doing in real time — not just what a code says.

2

Comprehensive Quote

We call or walk you through every finding. You get a written estimate with no hidden fees. Parts costs, labor costs, and estimated completion time — all in writing before any work begins.

3

Precision Repair

Whether it's replacing a $12 sensor or rebuilding a top end, our ASE-certified techs perform every repair to manufacturer specifications using OEM or premium parts.

4

Road Test & Verification

After repair, we clear codes and conduct a road test to confirm the fix. We then verify the code doesn't return before handing back your keys.

5

Full Repair Report

You leave with a printed report of everything we found, everything we fixed, and what to watch for in the future. Your 2-year/24,000-mile warranty is documented in the report.

FAQ

Engine Repair Questions

A steady check engine light usually means bring it in soon — not necessarily a breakdown emergency. A flashing or blinking check engine light is serious — it indicates an active misfire that can damage your catalytic converter. Pull over safely if the light is flashing and call us at (615) 555-0173. If the light is steady and the car feels normal, you can usually drive it to our shop.

Engine repair costs vary widely based on what's wrong. A sensor replacement might be $100–$300. An ignition coil or spark plug job typically runs $150–$500. Head gasket repairs start around $1,000. We never quote a price until we've actually diagnosed the problem — and we'll always present options when they exist.

Common causes include a low coolant level, a failed thermostat, a leaking radiator, a failing water pump, or a blown head gasket. If your temperature gauge is climbing toward the red, pull over immediately and let the engine cool. Do not open the radiator cap when hot. Call us and we'll advise — driving an overheating engine can cause catastrophic damage.

Related Services

Engine Diagnostics & Repair