EGR Valve Problems: Symptoms and Cleaning

EGR Valve Problems: Symptoms and Cleaning

It was a cold December morning last year, frost still on the ground, when Mrs. Johnson pulled her 2008 Honda Accord into the bay. She said the car had been hesitating on acceleration for weeks, idling rough like it wanted to stall at every stoplight, and that darn check engine light had been glaring at … Read more

Car Stalls at Idle: Troubleshooting Guide

Car Stalls at Idle: Troubleshooting Guide

Quick Answer: If your car stalls at idle—especially at red lights or when stopped—the most common culprits are a failing idle air control valve (IACV), vacuum leaks, a dirty throttle body, or a malfunctioning mass airflow sensor (MAF). Diagnosis starts with checking for error codes and inspecting hoses and sensors. Many fixes are DIY-friendly and … Read more

Mass Air Flow Sensor Problems: Diagnosis and Cleaning

Mass Air Flow Sensor Problems: Diagnosis and Cleaning

From a master tech who’s replaced 500+ MAF sensors: here’s exactly what fails, how to test it, and whether you can clean it or need a new one. Quick Answer MAF sensor problems typically show up as rough idle, hesitation, or poor fuel economy. Cleaning works 30-40% of the time if the sensor is just … Read more

Idle Air Control Valve Problems and Solutions

Idle Air Control Valve Problems and Solutions

Tuesday morning, 7:30 AM. A ’98 Civic rolls into my bay with the customer white-knuckled and frustrated. “It keeps dying at every stoplight,” she says, her voice cracking. The poor girl’s been nursing this thing for weeks, restarting it in traffic like she’s playing Russian roulette with rush hour. One quick scan, a $47 part … Read more

Why Does My Car Idle Rough When AC Is On?

Why Does My Car Idle Rough When AC Is On?

  Last Tuesday, 3:47 PM—heat index 104°F—a sweating guy in a 2016 Honda Civic LX rolled into my shop looking like he’d seen a ghost. “It’s doing this every time I hit the AC,” he said, mimicking violent shaking. His knuckles were white on the steering wheel. I popped the hood and saw it immediately: … Read more

Vacuum Leak Diagnosis: Finding and Fixing Leaks

Vacuum Leak Diagnosis: Finding and Fixing Leaks

It was 3:47 PM on a sweltering Tuesday in July when Mrs. Henderson’s 2012 Toyota Camry rolled into my bay. “It’s making this weird hissing sound, and the idle keeps dropping so low I think it’s going to stall,” she said, wiping sweat from her brow. I’ve heard this story hundreds of times, and my … Read more

Engine Rough Idle: Causes and Solutions

Engine Rough Idle: Causes and Solutions

Quick Answer: A rough idle is often caused by vacuum leaks, a dirty or faulty idle air control valve (IAC), worn spark plugs, or clogged fuel injectors. Start diagnosis with an OBD2 scan for codes, check for vacuum leaks, and inspect plugs and the IAC. Many fixes are DIY-friendly and cost under $200. It was … Read more

How to Diagnose Engine Misfires: Complete Guide

How to Diagnose Engine Misfires: Complete Guide

Quick Answer: What’s the fastest way to diagnose an engine misfire? Start with a scan tool to pull codes (P0300–P030x). Then swap coils or plugs between cylinders and see if the misfire follows. 90% of random misfires are ignition-related; 8% are fuel; 2% are mechanical. It Started on a Freezing January Morning It was 7:42 … Read more