Why a Car Suddenly Stalls
There are lots of reasons why a car may stall say at an intersection. One of the most common (and least known about) low automatic transmission fluid levels. Make sure you check the fluid when parked on a level surface.
Side point: While checking your oil do your best to NOT to allow any lint or dirt to contaminate the dip stick before reinserting. While not directly related, maintenance cycles for replacing transmission fluid and filter can vary and should be performed as suggested by the vehicle maker. A power flush may be totally worth it (if you can afford it) but it's not essential. It is a good idea though to consider a "power flush" when you find that the stalling problems continue to get worse. If and when your call continues to stall even after you just started it you should consider all alternatives to get it fixed before you have a vehicle breakdown or the car suffers from a more serious mechanical problem. Here are some of the reasons why your car may have a tendercy to stall:
Low transmission fluid level. Check the dipstick on the automatic transmission. Check the owner's manual for the correct procedure for your vehicle -- generally, manufacturers prefer testing with a warm engine.
A Clogged catalytic converter. Check under the section: stalling, no power when accelerating. Check under the section: the car at night after the vehicle has been running for a while; if the catalytic converter is glowing, it's probably clogged. You will have to replace the converter if you find this to be the problem.
Possible broken O2 Sensors. Check under the section: ideling. If initial idle OK after a cold engine start-up, but a warm engine idle will surge and stall. After a few thousand miles of this, most cars will turn on the "check engine" light.
A local mechanic can read the codes for you. There might be a number of reasons why the "check engine" light comes on, so it is good to get it checked out. Codes that show a lean mixture is a sign of O2 sensor failure. O2 sensors will generally last for about 60 to 75K miles.
You can buy an O2 sensor online for as little ast $50, and they're pretty easy to replace. Another reason is that the engine is idling too low (and, the idle is adjustable) or the control module is going out, which is cheap and easy to fix. Side point: If you check the fluid with the car running set the parking brake. Most vehicle's will ask you to put the car in Park or Neutral. Also, make certain that you do not have the car in gear.
Take heed of these warnings:
Sometimes there will be a need for you to reach into cramped and hot engine areas to check your fluid. Check your vehicle manual for its proper location. Take extreme care not to get burnt by hot engine parts. It's a good idea to wear long sleeve shirts or gloves as appropriate. Also, when you're adding fluid, it's also a good idea to use a clean funnel with an appropriate length of neck.
But do NOT overfill it!
Remember that there are two distinct types of transmission oil. make sure you use the proper type for your motor vehicle. You can find other helpful advice and information regarding why buy reusable air filters.