Check engine light diagnostics at your car
Steady or flashing, the light means your car's computer found a fault. We come to your driveway or work lot, read the codes and test what is behind them.
- We come to your home or work
- You approve the price first
- Most jobs finish in one visit
What the light may be telling you
Tools and parts come with the tech. Most jobs finish in one visit.
Steady or flashing: what each one means
Gas cars and light trucks from 1996 on have a self-check system called OBD II. When you switch on the ignition, the check engine light should come on briefly and then stay off while you drive. If it comes on and stays on, the system has found a problem. Your car may be wasting fuel, adding pollution or shortening the engine's life. That is no reason to panic, but it is a reason to have it checked soon.
A flashing light is more serious. It usually means a severe misfire, the kind that can damage the catalytic converter. Avoid high speed and heavy loads, and keep your time on the road short. Some owner's manuals say to stop in a safe place and let the engine cool. If the car shakes or loses power, park it and let us come to you.
What usually turns the light on
The cause can be small or serious. A loose or missing gas cap can set it off. So can a misfire from a worn spark plug or a weak ignition coil. Trouble in the emission controls, such as a failing oxygen sensor, a leak in the fuel vapor system or a worn catalytic converter, can trigger it too.
Reading the code is only the first step. A code tells us which system reported trouble, not always which part failed. The same code can come from a sensor, a wire, a vacuum leak or the part itself. That is why we test before we recommend a fix.
What to do now, and what we do on site
Start with the gas cap. With the engine off, make sure the cap is there and screwed on tight. If that was the cause, the light should go out after a few short trips. Also write down anything else you notice, like a smell, a new noise or a rough idle.
Our tech plugs a scan tool into the diagnostic port, usually under the dash, reads the stored codes and the data saved when the fault happened, and then tests the parts behind them. You get a plain answer and a price. No repair starts until you approve it.
The visit carries a standard diagnostic fee, and it counts toward the repair if you go ahead. We help drivers in Plano, Allen, Anna, Melissa and Princeton, in other towns across our Collin County area, and in Van Alstyne. To book, send the form on this page, start a chat, or call (214) 784-2056. Texts to that number work too, and we confirm the time with you by phone or text.
Three steps. Usually one visit.
Most jobs finish in one visit.
Book online or call
Tell us the symptoms, your vehicle and your address.
We come to you
Your driveway, your office lot or the curb. No tow, no waiting room.
We diagnose and repair on site
You approve the price before any repair work begins.
Good to know.
Can I keep driving with the check engine light on?
If it is steady and the car runs normally, you can usually drive gently until your visit, but do not put it off for long, since that can damage other parts. If it flashes, the car runs rough or a red warning light joins it, drive as little as possible and stop where it is safe.
Why did the light turn off by itself?
The computer turns the light off once the problem stops showing up, for example after a loose gas cap is tightened. If it keeps coming back, the fault is still there and worth a diagnosis.
Is reading the code enough to know what is wrong?
Not always. The code names the system that flagged a fault. Several different parts can set the same code, so guessing from the code alone can mean paying for a part you did not need.
Will my car pass the emissions test with the light on?
Usually not. Texas test rules fail a car whose check engine light is on with fault codes stored. In Collin County, gas cars from 2 to 24 years old are tested every year, and the registration cannot be renewed until the car passes. Clearing the code does not fix the cause.
What does a diagnosis cost?
We charge a standard fee to diagnose the car on site. If you approve the repair, we credit that fee toward it. You hear the repair price before any work starts, and the choice is yours.
Rattling, grinding
or not starting?
Tell us what is going on. A mechanic comes to your driveway with the tools and the parts.
Open 7 days