Is it safe to ignore a check engine light if the car drives fine?
When a car drives normally after a warning light comes on, drivers face a gamble between ignoring a potential catalytic system failure and spending thousands on repairs that might uncover deeper issues. This uncertainty makes it difficult to know if fixing the problem will actually secure the vehicle's long-term longevity or just waste money.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
- 1Driving the car until the fuel tank empties
- 2Using fuel system cleaner
- 3Switching to a higher octane fuel
- 4Having a mechanic clear the diagnostic trouble code
- 5Buying a new or different vehicle and taking on new car payments
- 6Sourcing a used low-mileage engine or a donor car with a compatible engine from a marketplace or auction
- 7ignoring the warning light and running the vehicle in two-wheel drive mode
- 8getting rid of the vehicle
- 9riding them out until they fail completely
- 10replacing the injectors immediately
- 11Trading in the vehicle before complete failure.
In their words
Unedited, most upvoted first, each linked to the thread it came from.
“If i drop around $2000 to fix the engine, will it be worth it? Im afraid they’ll be some underlying problems, but I’m really shooting for longevity.”source ↗
“My girlfriend has a 2018 Toyota CH-R 110k miles with a bad bearing in the transmission.”source ↗
“No shop will open it up and replace the bearing of coarse.”source ↗
“Anyway, my question is should I wait until the transmission fails or is it going to fail in a way thats dangerous?”source ↗
“Would that be that simple or do I to have to have a deeper look into my catalytic system?”source ↗
“Should I just ignore it or have a look at the catalytic system?”source ↗
“I am tempted to just ignore the light and let it run in 2wd mode. Do I risk damaging the transmission and other systems if I don’t it fixed?”source ↗
“four of them passed four of them failed according to them the ones that failed showed low output at various test points, which were around 9 to 10 cc low. Do y’all think I should just ride these injectors till they go out? Is that risky or should I replace injectors?”source ↗
“Injector place said I could ride them with no misfire or anything but they would probably replace them but as I said, I just got the car spent 200 to get them cleaned and was wondering if I should ride it out”source ↗
Where this came up
People with this problem also raised
- 6How to tell if a worn timing belt actually needs replacing
- 58Is it worth fixing an old car when repairs cost more than it's worth?
- 9Is changing your own oil actually worth it?
- 2Engine replacement vs head gasket repair cost
- 2Why is my check engine light on after changing the car battery?
- 11Is it safe to keep driving with needle bearings in the transmission pan?