What are the common causes of a Check Engine Light after an oil change?

Question

I just took both my cars in for oil changes and two weeks later both of the check engine lights came on in both cars. I had never been to this location before, but it was a chain. There is no other obvious problems besides the lights being on and I have driven 500 miles on both cars since the lights have come on. What did the company screw up or do to make this happen?

Answer 1

It could be that they didn't reset the computer when doing the oil change. Modern cars have a reset switch in the computer every time you do an oil change. It resets the oil life timer in the car. But for this to happen on both cars at the same time seems awful supicous. Check the oil level and go back to the place tell them what happend. If the oil level is way too low don't drive the vehilce. You can drive vehciles with a lot of problems but if the oil is ever tooo low it will definatley get damged.

Answer 2

I assume you immediately checked the oil level and it was correct, not perhaps high? Overfilling might cause a check engine light to come on. But if the level was where it should be, at the full mark, an oil change by itself wouldn't be the direct cause of a check engine light.

A check engine light comes on when any of the systems the computer monitors returns a value outside the range the computer expects to find. It can be anything from as simple as a gas cap not on tight, to a major engine problem.

So I'd suggest you quit ignoring the light, especially since it hasn't reset in 500 miles of driving, and take both vehicles in to be scanned. Once you know what error codes are stored, ask the mechanic "Could the recent oil change have anything to do with these codes?" and go from there. It may be just coincidence that you got trouble codes in both cars, it may not. So find out before any more time elapses.

Answer 3

It could be a number of things. Usually, in the lube system, it is due to the oil filter's internal by-pass system closing, thereby eliminating oil passing through the filter. This can happen due to extremely cheap oil filters and, at times, by heavy sludge buildup in the crank case which is loosened by the oil change.

If you are in a cold weather area, it could be an unrealted fuel system problem caused by gasoline freezing. This is very common if both vehicles commonly buy fuel at the same location frequently.

The best way to find out is to take the car to a mechanic and ask them to read the computer's "codes" which will easily identify why the light is on. The cost can be anywhere from zero to about $50.

Good luck!

Answer 4

The engine control system has detected a fault in the engine / emission systems. If your car is less than 10 years old (which it is) and has less than 100,000 miles on it, the problem is covered by the US federal emission control coverage provided under law by the manufacturer. So get an appointment scheduled with your local Subaru dealer, in most cases they will be able to repair it on the first visit but some less common issues may require them to order parts and that will necessitate a second trip to the dealer.

Answer 5

Thats awfully suspicious. First thing I would do is check the oil level. If it is low, take both cars back and explain that they need to remedy the situation.. They may not have put the drain plugs on securely.

Low oil level is the only thing I can think of for this.

Answer 6

if they are new cars they sometimes will use the check engine light instead of change oil, they might need to just be reset

Answer 7

Someone said put STP fuel injector cleaner in their my mechanic said not to do it when I put it in my truck it stalled since the fuel injector cleaner is made with jet fuel its to strong for the injectors. Like someone else said take it to your mechanic and have him scan both of the cars for trouble codes and see what it is before damage is done that can't be fixed.

Answer 8

it might now be a fuel injection problem. i had the same problem, and then i poured a bottle of stp into the fuel tank, and the light went out in about 20 miles afterward.

Answer 9

I have heard of quicky lube places relying on automated machines to fill the crankcase to the correct level, then not double checking the dipstick. One guy I talked to had his engine detroyed because of this. Might want to check the level on the dipstick.