OBD2 Diagnostics and Fault Codes

Car Scanner ELM vs Torque Pro 2026: Free, Android, iPhone Compared

Car Scanner ELM OBD2 vs Torque Pro 2026: free tier, platforms, customization, raw data. Side-by-side comparison with verdict and adapter pairing guide.

Carly Alternative Without Subscription: 5 Apps for BMW & Mercedes (2026)

Carly alternatives without subscription in 2026 for BMW and Mercedes owners. BimmerCode, BimmerLink, OBDeleven, Skanyx, Torque Pro compared. One-time payment options.

Carly vs OBDeleven 2026: Cost, Coding Depth and Which to Choose

Carly vs OBDeleven head-to-head 2026: pricing, BMW/Mercedes vs VAG coding depth, adapter lock-in, ongoing costs. Side-by-side comparison and verdict.

11 min

OBDeleven Alternative Without Subscription: 5 Apps Compared (2026)

OBDeleven alternatives without a subscription in 2026. BimmerCode, Carista, Torque Pro, Car Scanner ELM, Skanyx compared. One-time payment vs credits.

Used BMW i3 Buyer's Guide: Battery Health and Range Check

Three battery generations, REX quirks, and four OBD2 checks that separate a healthy used BMW i3 from a tired one. Before you pay 8,000 to 28,000 euros.

May 6, 2026

AdBlue Tampering: A 5-Minute OBD2 Check Before You Buy an EU Diesel

An AdBlue emulator or SCR delete is invisible on the dashboard but obvious in OBD2 live data. Five minutes during the test drive separates a real Euro 6 from a faked one.

April 28, 2026

EGR Delete Detection: What OBD2 Will (And Won't) Show on a Used Diesel

EGR deletion is the hardest of the three diesel emissions cheats to detect with OBD2. Here is what the scan tool reveals, what it cannot, and three physical checks that close the gap.

April 23, 2026

How to Spot a Deleted DPF on a Used Diesel Before You Buy

A removed diesel particulate filter is illegal across the EU and costs EUR 1,500 to 3,500 to refit. Six checks (three visual, three OBD2) catch it before you pay.

April 18, 2026

How to Check a German Used Car With OBD2 Before You Buy It

A 15-minute pre-purchase OBD2 scan tells you most of what the seller of an imported German used car would rather you didn't ask. Here is the exact checklist.

April 12, 2026

P0135 Code: Upstream O2 Sensor Heater Circuit (Bank 1 Sensor 1)

P0135 is the upstream companion to P0141. The heater in your pre-catalyst oxygen sensor has failed. Affects fuel economy more than P0141 because this sensor directly controls the fuel mixture.

3 min

P0300, P0301, P0302, P0303, P0304: Engine Misfire Codes Explained

P0300 means random misfires across multiple cylinders. P0301 through P0304 point to a specific cylinder. Here is how to tell which part failed, what it costs to fix, and whether you can keep driving.

6 min

P0340 Code: Camshaft Position Sensor Circuit Malfunction

P0340 means the ECU is not receiving a valid signal from the camshaft position sensor. Can cause no-start, rough running, or stalling. Usually a sensor or wiring issue with a straightforward fix.

3 min

P0446 Code: EVAP Vent Control Circuit Malfunction

P0446 means the vent valve in your fuel vapour system is not working correctly. Your car drives fine, but the code will not clear on its own and you will fail an emissions test. Simple diagnosis, cheap fix.

4 min

P0507 Code: Idle Control System RPM Higher Than Expected

P0507 means your engine idles too fast. Instead of 700-800 RPM, it sits at 1,000-1,500 RPM or higher. Usually a vacuum leak, dirty throttle body, or stuck idle air control valve. Easy to diagnose.

4 min

P0016 Code: Camshaft Position Correlation (Bank 1 Sensor A)

P0016 means the crankshaft and camshaft are out of sync. Usually a timing chain stretch, VVT solenoid, or oil issue. This can be expensive if ignored. Here is how to diagnose it and what to expect.

P0101 Code: MAF Sensor Range/Performance Problem

P0101 means your mass air flow sensor is sending readings outside the expected range. Usually fixable by cleaning, sometimes needs replacement. Full diagnosis and cost breakdown.

P0128 Code: Coolant Thermostat Below Temperature - What to Do

P0128 means your engine isn't reaching operating temperature fast enough. Usually a stuck-open thermostat. Here's how to confirm it, what it costs, and why you shouldn't ignore it through winter.

P0141 Code: O2 Sensor Heater Circuit (Bank 1, Sensor 2)

P0141 means the heater in your downstream oxygen sensor has failed. Your car runs fine, but emissions increase and fuel economy drops. A straightforward fix on most vehicles.

P0172 Code: System Too Rich - Diagnosis & Repair Guide

P0172 means your engine is running too rich, too much fuel, not enough air. Common causes, how to diagnose it yourself with live data, and what repairs actually cost.

P0174 Code: System Too Lean (Bank 2)

P0174 is the Bank 2 version of P0171. Too much air or not enough fuel on the opposite side of your engine. Causes, live data diagnosis, and repair costs for V6 and V8 engines.

P0401 Code: EGR Flow Insufficient - Diagnosis & Repair Guide

P0401 means your EGR valve is not flowing enough exhaust gas back into the intake. Common on high-mileage vehicles, especially diesels. Carbon buildup is the usual culprit.

P0430 Code: Catalyst System Efficiency Below Threshold (Bank 2)

P0430 is the Bank 2 version of P0420. Your catalytic converter on the opposite side of the engine isn't working efficiently. Causes, diagnosis with O2 sensor data, and what replacement actually costs.

BMW Fault Codes by Engine: N52, N54, N55 and What to Expect

BMW fault codes explained by engine family. VANOS, HPFP, turbo, oil leak, and DME codes for N52, N54, N55 with EU repair costs and diagnostic tool options.

October 25, 2025

P0300 Code: What It Means & How Much It Costs to Fix (2026)

P0300 random misfire explained. Flashing check engine light? Stop driving. Causes, diagnosis order, and repair costs in euros.

August 5, 2025

EVAP Leak: Common Causes & How to Find It (P0442/P0456 Guide)

EVAP leak causing a check engine light? P0442, P0455, P0456 explained. Start with the gas cap. Causes, diagnosis, and repair costs in euros.

May 5, 2025

12 min

How to Read OBD2 Live Data: Parameters, Normal Ranges, and What Each Value Means (2026)

How to read OBD2 live data: fuel trims, O2 voltages, MAF, coolant temp, throttle position, ignition timing. Normal ranges for each PID and what abnormal values mean in plain language.

April 15, 2025

15 min

P0171 Code: System Too Lean - Diagnosis & Repair Guide

P0171 explained: what system too lean means, the most common causes in order, how to diagnose with fuel trims, repair costs (€50 to €800), and when it's safe to drive.

February 20, 2025

13 min

What is OBD2? Complete Beginner's Guide to Car Diagnostics

Learn how OBD2 works, find the port in your car, understand diagnostic trouble codes, know which problems you can fix yourself, and when to see a mechanic.

February 10, 2025

P0420 Code: Catalyst Efficiency Below Threshold - Causes & Fix Cost

P0420 explained: what catalyst efficiency below threshold means, why it's not always the converter, diagnostic steps, repair costs (€150 to €2,500+), and when it's safe to keep driving.

January 20, 2025

How-To Guides

Check Engine Light: What It Means, Common Causes, and Repair Costs

Your check engine light is on. Learn what solid vs flashing means, the most common codes, how to diagnose them, and what repairs typically cost.

September 15, 2024

15 min

Best Car Diagnostic Tools 2026: Pricing, Multi-Brand Coverage & Repair Shop Picks

Side-by-side comparison of the best car diagnostic tools for 2026: scanners, apps, multi-brand coding tools, and professional repair-shop tablets. Real EUR pricing across every tier from €30 to €1,500.

August 30, 2024

16 min

OBDeleven Review 2026: Price, Carly Comparison, and Is It Worth It?

Honest OBDeleven review for 2026: real prices (device + PRO/ULTIMATE subscription), comparison with Carly, VCDS, BimmerCode, and Skanyx, plus what it does and doesn't do on VW Group, BMW, Toyota, and Mercedes.

August 25, 2024

Best OBD2 App 2026: Free, Android, iPhone Apps Compared

Best OBD2 app 2026: free, Android, iPhone tested. Car Scanner ELM, Torque Pro, OBDeleven, Carly, BlueDriver, Skanyx compared. Pick the right one for your car.

August 20, 2024