Hey I recently installed an APC performance air filter on my 2001 volvo s40 1.9t and once I installed it my check engine light came on, I am pretty sure its because of the cord I unplugged but am unsure what it does. Ive checked all my brakes and signals all of them work, maybe you can help me out.


This is what I disconnected


and I painted my grill black

and my rims

my ride


Thanks alot!
P.S. it sounds really good, you can hear the air getting sucked in and when you let off the gas it sounds quite like a BOV

 

That is the mass flow sensor you unplugged. The car needs it to run right. You need to remove it from the air box and put it back in.

 

Thanks alot, I just did it and my engine light is still on, so it is probably something else.

Thanks again!

 

No once you put it back on the codes need to be cleared. It won't go out by itself. AutoZone should be able to clear it for you.

 

just got back, everything is working good now thanks for your help