So,

It seems like every few hundred miles the CEL comes on with some other problem. It's a never ending deal with this car (2001 S40 w/83,000).


This time it's P0301 (misfire) and it shows the problem being on every cylinder, although the car runs smooth as silk.

Also had P0172 (MAF?) indicating the car is running too rich.


Is it just that the car will throw a code for no dang reason other than to put me in a foul mood?


Frustrating for sure..

 

Lol. I'm thinking the misfire is what caused the rich code as too much unburned fuel is making it to the O2 sensor. Maybe time for a set of spark plugs? Or maybe just regap your old ones a bit tighter, like .028". Definitely remove a spark plug and give it a look. Make sure it's not covered in black soot.

 

Yeah,

I'm planning on a set of plugs this coming weekend.