We are a team of ASE certified mechanics that have created this guide to help you understand if your car is safe to drive with the check engine or service engine soon warning on light on.
If the warning light comes on there are basically two different scenarios to look for. First, if nothing seems to be wrong with the engine or transmission and the car is driving okay it most likely means a non-invasive sensor has failed or a simple mechanical failure is present such as a small vacuum leak. You can continue driving without additional damage to any components. This is because the computer is equipped with a predetermined value for each sensor which enables the engine to keep running without an issue. The computer will store this problem in the form of a trouble code, this gives you time to get the car to the repair garage or read the codes yourself and perform the repairs.
The next set of situations are either right before or just after the check engine light has come on, and you hear or feel something strange in the way the engine or transmission is operating. The first thing to look for is the reading on the engine temperature gauge or if the engine temperature warning light is on, in this case you must pull over in a safe area and shut the car off. This will save the engine from serious internal damage. If you can feel the engine misfiring it can cause the catalytic converter to overheat and melt internally due to the unburnt fuel being processed which will require a catalytic converter replacement. The car's computer also monitors the automatic transmission and can tell if the transmission is slipping. This could be due to a loss of fluid in which case if you continue to drive the transmissions can burn up which would require a full transmission rebuild.
Personal safety should be your biggest concern. If you must pull over search Google for the closest tow truck company using your phone, also check their reviews. Likewise do the same for a repair garage in your area.
Please watch this video of the job being done, then continue down the guide to glean additional helpful information.
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