Exhaust · Sensors · Emissions

Exhaust & Emissions Repair in Johnson City, TN

More than a loud muffler.

A rattling exhaust and a check engine light are often connected to the same system. Our ASE certified technicians repair exhaust pipes and mufflers, and diagnose the oxygen sensors, EVAP components, and airflow sensors that trigger most emissions-related warning lights.

Call (423) 913-3111 Schedule Service

Exhaust Noise and Check Engine Lights Often Share a Cause

People usually think of exhaust repair as fixing a loud noise, and sometimes that's all it is. But the exhaust system also carries the sensors your engine relies on to run cleanly and efficiently, and a leak, a failed sensor, or a stuck valve anywhere along that path can trigger a check engine light long before you hear anything different. We test the whole system, not just the pipe.

What we service

Exhaust & Emissions Components

Exhaust Pipes & Muffler

Rust and corrosion eventually create holes or loose connections, causing a louder exhaust note, rattling, or a drop in performance. We repair or replace the damaged sections.

Catalytic Converter

Converts harmful exhaust gases into less harmful ones. A clogged or failing converter causes reduced power, a rotten-egg smell, and can fail an emissions test.

Oxygen Sensors

These sensors measure exhaust oxygen so your engine can maintain the right air-fuel mixture. A failing O2 sensor is one of the most common single causes of a check engine light, and can hurt fuel economy noticeably before you notice anything else. See our check engine light diagnostics.

EVAP System

Seals fuel vapors inside the tank instead of letting them escape. A loose gas cap, a cracked hose, or a stuck purge valve are common, often simple, causes of an EVAP-related warning light.

Mass Airflow (MAF) Sensor

Measures incoming air so the engine can calculate the right fuel amount. A dirty MAF sensor causes rough idling, hesitation, and poor fuel economy. We clean it where that resolves the issue, and replace it when it doesn't.

EGR Valve

Recirculates a small amount of exhaust gas to reduce emissions. A stuck or clogged EGR valve can cause rough idle, stalling, or a check engine light.

Signs Worth Checking

Loud, rattling, or noticeably louder exhaust noise
A rotten-egg or sulfur smell from the exhaust
Thick blue, black, or white smoke, especially at startup
A check engine light, particularly one related to emissions, fuel trim, or oxygen sensor codes
Noticeably worse fuel economy with no other explanation
Rough idle or hesitation that doesn't point to an obvious cause

Many of these symptoms overlap with electrical and wiring issues too, since sensors communicate through the same systems we cover on our electrical system repair page. We diagnose across both to find the real cause rather than guessing at parts. We service exhaust and emissions systems on cars, trucks, SUVs, and 4x4s, domestic, import, and European, including BMW, Mercedes-Benz, and Audi. We diagnose before we quote, and we never sell a repair you don't need. Every qualified exhaust and emissions repair is backed by our 36 month, 36,000 mile nationwide warranty on parts and labor.

How Much Does Exhaust or Emissions Repair Cost?

It depends entirely on what's actually wrong. A gas cap or a sensor is a small repair. A catalytic converter or a full exhaust section costs more. We diagnose first with real testing, then give you a real, itemized price for your specific vehicle, not a phone guess.

Customer reviews

What Our Customers Say

"From the initial conversation, to setting the appointment, to dropping off my car, the diagnosis process, and picking up my automobile, and the price, all exceeded my expectations."

Alan E.

"Great service, and the gentlemen who waited on us were excellent at explaining the issues."

Regina J.

"Always fair and good humored. I don't take my car anywhere else. They're reliable, and that's what you want out of your cars mechanics and technicians."

Buddy A.

"Been going to these guys for years. Always a great experience."

Bryan B.

Read more reviews on Google: Market Street (700+) · Hopper Road (90+)

Two shops in Johnson City

Bring Your Vehicle to Either Location

Location One

West Market Street

3832 W Market Street
Johnson City, TN 37604

(423) 913-3111

Call Shop Directions

Location Two

Hopper Road

216 Hopper Road
Johnson City, TN 37604

(423) 328-7036

Call Shop Directions

Common questions

Exhaust & Emissions FAQ

What causes a loud exhaust noise?

Usually a hole, crack, or loose connection somewhere in the exhaust pipes, muffler, or a rusted-through section. Corrosion is the most common cause, especially on older exhaust systems.

What does an oxygen sensor do, and why does it fail?

It measures exhaust gas to help the engine maintain the right air-fuel mixture. They fail from age, contamination, or wiring damage, and a bad one is one of the most common causes of a check engine light.

What is the EVAP system?

The evaporative emissions system keeps fuel vapors sealed inside the tank instead of releasing them into the air. A loose or damaged gas cap, a cracked hose, or a stuck purge valve are common causes of an EVAP-related check engine light.

Do you clean or replace the MAF sensor?

Yes. A dirty mass airflow sensor can cause rough idling, hesitation, and poor fuel economy. We clean it in many cases, and replace it when cleaning doesn't resolve the problem.

How much does exhaust or emissions repair cost?

It depends entirely on what's actually wrong. A gas cap or sensor is a small repair. A catalytic converter or a full exhaust section costs more. We diagnose first and give you a real, itemized price.

Is exhaust and emissions work covered by a warranty?

Yes. Qualified repairs are backed by our 36 month, 36,000 mile nationwide warranty on parts and labor.

Serving Johnson City and the Tri-Cities

We handle exhaust and emissions repair for drivers across Johnson City, Jonesborough, Gray, Telford, Chuckey, Elizabethton, Erwin, Fall Branch, Kingsport, Limestone, Piney Flats, and throughout Washington, Carter, and Unicoi counties. See our full list of services, learn what sets our shop apart, or head back to our home page.

Noise or a warning light, we'll find it

Let's get your exhaust and emissions sorted out

From a rattling pipe to a stubborn check engine light, our ASE certified team tests the whole system.

Schedule Service Call W Market St Call Hopper Rd

W Market St · (423) 913-3111 Hopper Rd · (423) 328-7036