The “check engine” light in my 2000 Volvo S70 is on and the mechanic says it indicates the mass flow sensor is out of spec. The car runs very smoothly. How much risk do i incur by ignoring the check engine light. The car has a history of “fixing itself”–meaning the check engine light goes out after a while.
What will really happen is that your gas milage will decrease.
There are two problems with that. First you will likely have lower fuel mileage, which will cost you. Next you will not know if something else happens. This one could be very expensive.
If you are questioning the mechanic, how about having the code read by someone else, like an auto parts store (some will do it for free) and post it back here (it will be something like “P0123” Then we may be able to offer you some suggestions.
You say you have had this before. My guess is it is marginal and since you have not yet fixed it, it is continuing to trigger the CEL. Maybe it is time to fix it. If it is marginal it could have been lowering your mileage all this time.
Perfectly stated Joseph. OP, pay particular attention to Joseph’s second paragraph. You’re risking losing far more money than your initial gamble. Far more than the cost of a new MAF sensor.