Skip the auto shop - Our mechanics make house calls

Q: Vehicle slightly trembles in idle, just started today.

asked by on

I recently had my spark plugs replaced, replaced my radiator, had a belt replaced, an oil change, and had my head gaskets replaced. Today I noticed that my car slightly trembles while in idle. I've also noticed my car losing power when going uphill, it lags big time. Also, my check engine light came on a couple of days ago, and got a code. The code was for a small exhaust leak, and the clerk told me it shouldn't be a problem. I'm hoping it's just a loose spark plug? Someone help!

My car has 135000 miles.
My car has an automatic transmission.

This may be a result of a faulty oxygen sensor. As you may know the oxygen sensors which are part of your emissions system read exhaust gases to determine whether or not the appropriate amount of oxygen is present in the exhaust. Based upon this reading, this information is relayed to the car’s ECU which then makes a determination as to whether or not to add more or less fuel to the engine. When too much or too little oxygen is present, this will cause check engine light to come on. Too much oxygen may be present in the exhaust gas due to things like an exhaust leak, a vacuum leak, a faulty mass air flow sensor (causing a lean fuel condition) or faulty fuel injectors. Too little oxygen may be present in the exhaust gas may be caused by things like a clogged air filter, a failing mass air flow sensor (causing too much fuel to be introduced to the motor), bad fuel injectors or a clogged catalytic converter. When the O2 sensor is not working properly, this will cause false readings to be relayed to the computer causing inaccurate adjustments to be made to the intake and fuel system in your engine. I would suggest having an expert from Your Mechanic come to your home to diagnose your emissions system.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  1. Home
  2. Questions
  3. Vehicle slightly trembles in idle, just started today.

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

Get a quote

What others are asking

Q: Sudden jerk upon acceleration, low gas mileage - 2013 Range Rover

Hey there, thanks for writing in about your 2013 Range Rover. You may have a problem with the throttle control that may be dangerous to drive. There are many other possibilities, such as a vacuum leak, faulty mass air flow...

Q: Car shakes and pulls when driving

Hi. The lights you are mentioning have been caused by loose or corroded battery terminals. The symptoms you are experiencing sound like an engine component position sensor. The engine's computer relies on the values from the crankshaft and camshaft position...

Q: Fuel pump not priming

Hi. The first priority is to get the vehicle to crank over, without engine/camshaft RPM's, the engine computer will not start up the fuel pump. The starting circuit needs to be diagnosed. Some of the causes could be an ignition...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.