Q: Muffler is loud and the van jumps when in idle. When it jumps the muffler makes a puffing noise and smells.

asked by on November 03, 2016

Loud muffler. Van Jumps forward in idle and RPM goes up. When the van jumps, the muffler puffs simultaneously and smells.

My car has 150000 miles.
My car has an automatic transmission.

Smell in the car Inspection $79.99 - $99.99 Get a Quote
Catalytic Converter Replacement $291.63 - $3224.07 Get a Quote
Idle Control Valve Replacement $147.54 - $995.01 Get a Quote

This may be related to a failing catalytic converter or potentially a dirty or failing idle air control valve. The idle air control valve reads the air intake as it enters the motor and relays this information to the computer which makes adjustments to fuel. When this is not working properly, you may experience an intermittent idle problem as you have experienced. This may also cause a rich fuel condition producing a smell of fuel as well.

To avoid any unnecessary repairs, I would recommend having an expert from YourMechanic come to your location to diagnose the smell and noise firsthand. One the issue has been pinpointed, the mechanic can service the catalytic converter or idle air control valve as necessary. Best of luck.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing


Experienced Mechanic?

Earn up to $70/hr

What others are asking

The speedometer needle falls down when I drive, what could be the problem and how do I fix it? Thank you in advance

This could be related to a couple of possibilities. The [instrument voltage regulator]((https://www.yourmechanic.com/services/instrument-voltage-regulator-replacement) regulates the voltage supplied to the various gauges in your vehicle’s dash. When this is not working properly, this may cause the gauges in your dash to...

Seemingly misfires

Hi...your vehicle has an on-board diagnostic system, albeit the early version known as OBD-I. What I would therefore recommend, to get this engine running condition diagnosed and repaired, is you request a check engine light diagnostic. The trouble codes that...

Need help with a reduced engine power warning light.

Hello - first thing to check is what problem code remains set. If still a TPS, double-checking the wiring at the throttle body, and also checking the throttle pedal actuator sensor. This is the "transmitter" whereas the throttle position sensor...

Turn key to start, lose all power, it resets and starts. Battery is not dead.

If you are losing all battery power intermittently but your car's battery is testing good, check the battery clamp connections to the cables for corrosion. The cables will show green tinted corrosion at or near the connections where the cables...

Hazard lights wont turn off 2005 Toyota 4 runner

Hello. It sounds like the switch is bad for the hazards or more commonly it sounds like a relay failure. The circuit would need to be tested with a voltage meter to be able to tell for sure, but it...

Radiator fan cover???

Thanks for writing in about your 2003 Infiniti J35. This is the radiator fan shroud upper and lower. They are the same as a radiator fan cover. If you need to have a technician inspect your the noise to verify...

Broke vapor line on fuel pump assembly, could i still drive car without any issues?

You should not drive it this way. Did you know that gasoline vapor is more flammable than liquid gas? You should have it fixed before driving it to be on the safe side. If you need assistance with this, seek...

Car shakes heavily when I brake

The shaking when you brake is most likely caused by one of more of your brake rotors being warped. Your steering wheel not being straight could be due to a worn suspension component in the front of your Jeep. This...

How do I adjust the front head restraints?

Each front seat has a head restraint to help protect the driver and the front seat passenger in the event of an accident. When you get in the vehicle, you should adjust your head restraint so that the top of...

Related articles

5 Red Flags That Your Car Needs Immediate Attention
It It isn’t popular to think about, but you should be prepared for vehicle problems. Vehicles are designed and built by people, and they are only as perfect or flawed as the people who build them. That means sooner or...
How to Troubleshoot a Car Exhaust or Engine Noise
Car exhaust systems and car engines make whirring, clicking, or sputtering noises if there's a faulty belt, alternator, water pump, or tension pulley.
The Top 10 Most Problematic Cars
All cars have issues, from grinding brakes to gasket leaks. The Ford Explorer's and Honda Civic's bad transmissions rank them as the most problematic.