What we handle
Exhaust system services we handle in Mays Landing
The exhaust system is more than the muffler. Most of what we handle starts further upstream and comes out at the tailpipe, and most of the diagnostic time goes to the part you cannot hear from the driver's seat.
Diagnosis and welding
Exhaust leak smoke testing, flex pipe replacement, mid-pipe sections, manifold gasket repair, heat shield re-fastening. Welding done in-house, not contracted out.
Common examples: Smoke-test leak detection, Flex pipe replacement, Mid-pipe welding, Heat shield repair
Catalytic and emissions
Catalytic converter replacement after a P0420 or theft, oxygen sensor replacement, and emissions system services after an MVC inspection rejection.
Common examples: Direct-fit converter, CARB-compliant universal, Upstream / downstream O2, NJ emissions repair
Muffler and pipes
Muffler replacement for blown or rusted units, resonator and mid-pipe repair, tailpipe replacement.
Common examples: Muffler replacement, Resonator repair, Mid-pipe sections, Tailpipe replacement
Custom and trucks
Pickup and Jeep mid-pipe fabrication, hanger relocations after lift kits, axle-back installs from a parts kit you supply, rust-replacement welds. Performance-tuned headers and dyno setups go to a specialty shop.
Common examples: Mid-pipe fabrication, Hanger relocation, Axle-back installs, Rust-replacement welds
NJ 39:3-70 covers the muffler equipment requirement; a missing or modified muffler is a roadside-summons item, not just an inspection one. We work inside both the federal EPA emissions rules and NJ DEP standards and document everything on the invoice so the paperwork holds up at re-inspection.
Signs you may need exhaust system repair
Exhaust trouble shows up in patterns we have read for over forty years, and most of the time the symptom tells us where to look before the car is on the lift. Two or more of these at once means it is time to schedule.
Sudden increase in engine noise
A blown muffler, a cracked flex pipe, or a missing catalytic converter all change the volume overnight. Flex pipe is the most common cause; muffler is the assumption most owners make.
Hissing or popping during acceleration
A leak in the manifold or upstream of the converter pulses with engine RPM. Often louder when the engine is cold and the metal has not expanded into seal.
Exhaust smell inside the cabin
Do not delay. Carbon monoxide from an exhaust leak that finds the cabin is dangerous, and the leak point is almost always upstream of the catalytic converter.
Rotten-egg smell from the tailpipe
Hydrogen sulfide passing through a failing catalytic converter unconverted. The cat is no longer doing its job on the sulfur compounds in the exhaust.
P0420, P0430, or oxygen-sensor codes
Diagnose the cause; do not just swap the converter and hope. Most P0420 codes trace upstream to an O2 sensor, an exhaust leak, or a misfire, not a failed converter.
Rattle from underneath at idle or over bumps
A heat shield, a broken hanger, or substrate breakdown in the converter. The diagnostic answers it in five minutes on the lift, not from the driver's seat.
Emissions code from the exhaust system
An exhaust leak or a failed catalytic converter can set a P0420 or P0430. We are a licensed NJ inspection station, so the re-inspection happens here once the repair is done, not across town.
Loss of power under acceleration
A clogged or collapsed catalytic converter restricts flow and chokes the engine. Most common on higher-mileage vehicles that have been running rich for a long stretch.
Two or more at once, do not wait. The cheapest version of an exhaust fix is the leak. The expensive version starts with a catalytic converter.
Exhaust system repair for Mays Landing and Atlantic County drivers
Same family, same eight bays, same corner of Mays Landing since 1981. We serve Hamilton Township, Egg Harbor Township, Northfield, Somers Point, Estell Manor, Cologne, Galloway, Folsom, Buena Vista, and the rest of Atlantic County. Fred Kneble has been turning wrenches here for decades. Nancy Kneble runs the shop and the books.
Atlantic County has its own exhaust pattern. Salt air rots mufflers and exhaust hangers faster than inland counties. Catalytic converter theft has been a steady issue, especially on Priuses, Tacomas, and any vehicle parked overnight at marinas or apartment lots. NJ Title 39 keeps the regulatory side strict. We see the full spectrum, from a 2008 Civic with a coffee-can-loud muffler to an F-150 that flunked emissions on a P0430. We can diagnose and repair exhaust-system problems, then explain where the vehicle must go for any required re-inspection.
Helpful details to mention
- Vehicle year, make, model, and engine size
- Mileage
- Whether the check engine light is on, blinking, or off
- Any codes a code reader pulled (P0420, P0430, P0171, P0300, O2 codes)
- When the noise or smell started and what changed (cold start, after a pothole, etc.)
- Whether a warning light or code is showing
- Whether you suspect a stolen converter (loud roar on cold start)
- Whether the car smells inside the cabin or only outside
The more we know up front, the more accurate the estimate.
Customer proof
Service was performed quickly and the Kneble Team provided great communication throughout the visit.Robert Orzechowski, Google review
Questions before scheduling?
Talk with us about Exhaust System Repair
Tell us the year, make, model, mileage, and what changed. If it is a flex-pipe weld, we book the visit. If it is a converter, we diagnose first so the bill matches the actual cause.
Service guide
Exhaust System Repair Service Guide
Topic-based reference for how the exhaust system works, the diagnostic differentials we run on the most common complaints, the NJ inspection rules that govern exhaust work, and the most common questions drivers bring through the door.
In this guide
01 of 06, When a
When a P0420 is not the catalytic converter
P0420 and P0430 measure catalyst efficiency, but the most common root cause is an upstream leak or a tired downstream oxygen sensor, not a failed converter. The code itself only tells you that the downstream oxygen sensor signal is not different enough from the upstream signal. That can mean the converter is dead, or it can mean the downstream sensor has aged into signal drift, or it can mean an upstream exhaust leak is letting fresh air confuse the math.
Read more about When a P0420 is not the catalytic converter
We diagnose before we quote. The Opus scan tool reads upstream and downstream oxygen sensor signals live, and the comparison tells us which fault is actually firing. A drifted downstream sensor reads flat-line at part throttle when a healthy one cycles. An upstream leak shows up as a long-term fuel trim that runs lean past 10 percent. A misfire that has been dumping unburned fuel into the converter prints freeze-frame data the generic code reader never sees.
What matters for this work is that we are a licensed NJ inspection station, so Egg Harbor Township and Mays Landing drivers can have us re-inspect after the repair. For the broader scan workflow on any check-engine-light caller, see our check engine light diagnostics page; for the sensor-specific story, see oxygen sensor replacement.
Got a P0420 quote you want a second opinion on?
Call (609) 625-3286From the shop library: Article Car Exhaust Fumes: Where Do They Come From and Are They Harmful? Video Why Driving Your Vehicle Can Turn Off Your Check Engine Light
02 of 06, Sudden loud
Sudden loud exhaust: usually the flex pipe, sometimes the muffler
The flex pipe just ahead of the catalytic converter cracks first because it flexes every time the engine torques, and most "I need a new muffler" calls in Hamilton Township and the surrounding towns are actually a $90 weld on a $25 flex pipe. The flex pipe is a short corrugated section of stainless braid that absorbs engine movement. It is also the part of the exhaust that lives directly under the hottest section of the engine bay, soaks the most road salt, and flexes thousands of times per drive cycle.
Read more about Sudden loud exhaust: usually the flex pipe, sometimes the muffler
Diagnostic differential, most common to least common
- Flex pipe (most common)
- Visible crack or hole in the braid, often with a sooty stain on the heat shield above it.
- Detail
- Cracked exhaust manifold or blown gasket (second most common, older domestic V6s and V8s especially). Hissing pulse with engine RPM, often louder when cold.
- Missing catalytic converter from theft (rising in our area)
- Sudden roar from cold start with no other symptoms, and a sawed pipe visible under the vehicle.
- Muffler rust-through or blown baffle (less common than people assume)
- Deep rumble that grows over weeks, not overnight.
When the diagnosis points at the muffler, we say so plainly, and the muffler replacement page covers the parts-and-labor scope. When the diagnosis points at the flex pipe, you keep your muffler.
From the shop library: Article Comparing OEM Catalytic Converters vs. Aftermarket Catalytic Converters Video Why Your Check Engine Light Does Not Turn Off After A Repair
Tell us what changed, when it started, and what you drive. We can help decide whether to start with an inspection, alignment check, or related repair.
03 of 06, If your
If your catalytic converter was stolen
A roar on cold start with no other symptoms on a Prius, Honda CR-V, F-150, or Tacoma is almost always theft, not failure, and a CARB-compliant universal converter often passes NJ inspection at a fraction of direct-fit cost. Theft cuts are visible from underneath; the converter is just gone or sawed in half, and the cut ends of the pipe are bright steel rather than rusted black. A failed converter is in place but throws a P0420 or P0430, and the car still sounds normal.
Read more about If your catalytic converter was stolen
Direct-fit vs CARB-compliant universal
- Direct-fit is a vehicle-specific bolt-on. Matches OEM emissions hardware, easiest install, highest cost.
- CARB-compliant universal is welded into the existing pipework. Carries the federal emissions warranty and the CARB EO number that NJ inspection accepts. Lower cost, longer labor.
- Non-CARB universal is cheaper still and fails NJ inspection. We do not install them.
A theft-victim invoice should document the make, model, VIN, the CARB EO number of the replacement, and the date so your insurance claim has the paperwork it needs. The full scope for this work lives on the catalytic converter replacement page. As a licensed NJ inspection station, we also handle the re-inspection once the exhaust repair is complete.
From the shop library: Video The Different Colors of Cooling Fluid
04 of 06, How exhaust
How exhaust repair links to NJ state inspection
A P0420 or oxygen-sensor code fails the OBD-II portion of NJ inspection; a missing muffler is a roadside summons under NJ Title 39:3-70, and the drive cycle that resets monitors after repair takes a specific pattern most owners do not know. We have spent decades inside that rule set, and we run our drive cycle on Somers Point Road and Route 40 because the route hits the speed and load conditions the catalyst monitor needs to set.
Read more about How exhaust repair links to NJ state inspection
A car that just had a converter installed will fail inspection if you drive it straight to the MVC. The catalyst and oxygen-sensor monitors live in a "not ready" state until the OBD-II computer sees enough operating conditions to confirm the new hardware is doing its job. That can take a half-hour of mixed driving, or it can take two days, depending on the platform. Our emissions system services page goes into the monitor-by-monitor detail.
Federal emissions warranty (8 years / 80,000 miles)
The Clean Air Act covers the catalytic converter for 8 years or 80,000 miles from the original in-service date. If your car is inside that window and the converter genuinely failed, the dealer covers it under warranty. We will not bill you for a converter we can prove is dealer-warranty-eligible; bring the proof and we will route you to the dealer.
NJ 39:3-70 muffler equipment rule
A missing, modified, or excessively-loud muffler is a separate statute from the inspection code, and a Folsom officer can write the summons whether or not your sticker is current. For the broader inspection workflow, the NJ state inspection page is the place to land before your sticker expires.
From the shop library: Article Should I Repair or Replace My Vehicle? Video Questions to Ask Yourself When Purchasing a Used Car
Tell us the year, make, model, and what you are noticing, and we will say what to check first.
05 of 06, Custom truck
Custom truck and Jeep exhaust welding in-house
Pickup, Jeep, and aftermarket exhaust welding happens in our bays, not contracted out, with the scope-shield that performance-tuned headers and dyno setups still go to a specialty shop. We have a welder and a fabricator on staff, and the rotary lift gives us the room to run a mid-pipe from manifold to tailpipe without dropping the body.
Read more about Custom truck and Jeep exhaust welding in-house
In scope
- Mid-pipe fabrication and welding
- Hanger relocations after lift kits
- Axle-back muffler installs from a parts kit you supply
- Rust-replacement welds on rotted sections
- Exhaust tip replacement
- Custom mid-pipe routing for aftermarket cat-back kits
Not in scope
- Full dyno tuning
- EPA-illegal catalytic converter deletes
- Off-road-only headers on a street-driven vehicle
- Race-only systems that fail NJ inspection by design
We tell you up front when a request lives outside our scope and where to take it. Honest scope is part of how we keep the AAA Approved status.
From the shop library: Article Three Essentials for Road Trips After The Quarantine Video The Difference Between Check Engine Light vs. Service Engine Soon Light
06 of 06, Exhaust services
Exhaust services and related spoke pages
Exhaust work splits into focused spoke pages plus the broader leak diagnosis and manifold work we keep here. The linked pages below have the deeper part-specific detail.
Read more about Exhaust services and related spoke pages
Call the shop or request an appointment and include the vehicle year, make, model, mileage, and symptoms.
FAQs
Exhaust system repair FAQs
My car is suddenly loud. Is it the muffler?
Sometimes. More often it is the flex pipe ahead of the converter, a cracked manifold, or a missing catalytic converter from theft. A loud car gets a real diagnosis before any part comes off, because a new muffler does not fix a leak somewhere else upstream.
How long does an exhaust leak repair take?
A welded flex pipe or single-flange leak is usually a same-day job. A manifold replacement on a V6 or V8 takes longer because the part lives behind heat shields, motor mounts, and other components. We give you the timeline with the estimate.
Will I fail NJ inspection because of an exhaust leak?
An exhaust leak that throws an oxygen-sensor or catalyst code will fail you on the OBD-II portion. A leak that does not throw a code will not fail inspection, but it can still draw a township summons under NJ 39:3-70 for the muffler equipment rule.
Can I weld a muffler instead of replacing it?
Sometimes, if the leak is at a seam or a hanger weld and the body of the muffler is sound. A rust-through on the canister itself is a replacement, because welding wet rusty steel is a short-term fix that comes back in months.
Is my converter stolen or just failed?
Theft cuts are visible from underneath; the converter is just gone or sawed in half. A failed converter is in place but throws a P0420 or P0430, and the car still sounds normal. The diagnostic answers it in five minutes on the lift.
My catalytic converter is under warranty. Will you replace it?
If your vehicle is inside the federal 8-year / 80,000-mile emissions warranty and the converter genuinely failed, the dealer covers it. We will not bill you for a converter that should go on the dealer's tab. Bring proof of in-service date and we will route you to the dealer with the diagnostic write-up.
Why is my tailpipe dripping water?
Water is a normal byproduct of combustion and you will see drip at cold start. A constant flow of water, antifreeze, or oil is not normal and points to an engine concern, not an exhaust one.
What about the rattle from underneath?
Usually a heat shield, a broken hanger, or substrate breakdown inside the converter. We pinpoint it on the lift, not by guessing from the driver's seat.
Further reading and viewing
Related Kneble's coverage for exhaust and emissions
Exhaust and emissions content from the Kneble's library if you want to dig deeper before scheduling.
Related articles
Car Exhaust Fumes: Where Do They Come From and Are They Harmful?
Should I Repair or Replace My Vehicle?
The Dangers of Driving Your Car Through Flood Water
Comparing OEM Catalytic Converters vs. Aftermarket Catalytic Converters
Local shop
Visit Kneble's in Mays Landing
5473 Somers Point Road, Mays Landing, NJ 08330
Five minutes off Route 40 between the Hamilton Mall and Lake Lenape. Ten minutes from the Atlantic City Expressway Exit 17. Twelve minutes from EHT and Northfield. Fifteen minutes from Somers Point. Freddy J's Bar & Kitchen is nearby at 5698 Somers Point Road if you want to grab food before or after the appointment.
- Mon to Fri 8am to 5pm
- Saturday 8am to 4pm
- Sunday Closed
Reviews
Trusted by South Jersey drivers
Customers come to Kneble's for clear communication, practical recommendations, and repairs handled by a local team they can reach directly.
Friendly receptionist. In and out within 45 mins.
Janet Jackson, Google review
Service was performed quickly and the Kneble Team provided great communication throughout the visit.
Robert Orzechowski, Google review
Excellent quick service by personable staff and very qualified techs at a reasonable charge.
Glenn Peterson, Google review
Very good service here. Treated us very well. Great conversation with Carmen.
Gary Mazzone, Google review