From reading the forum I am aware that many others had this problem with their s40's. My s40 is a 2001 with 50 some thousand miles on it. Like others durring hard acceleration my engine would sputter. I took the advice from the other posts and took out my fairly new Autolite plugs and put in the volvo plugs. That seamed to fix the problem, but about three times while at a stoplights and in drive the engine sputtered on me. The sputter was real quick and felt hard. I am woundering if this could be part of the original problem that the spark plugs fixed to a point, but did not fix the problem all the way? Could the coils be the problem and maybe the plugs made the problem not that noticable, or if the coils are bad could the problem come back when the plugs get older? My check engine light is saying lit to. Has anyone figured what exactly is causing this? I appreciate the help, Thanks

Skatermattc2

 

Coils get my Vote

 

ya coils got my vote too!

 

Ok I will buy a pair. I think I will rent a code getter also just to check things out. Ill post up the results and tell if the coils work. I reall appreciate your help. It would cost a fortune to have a shop tell me whats wrong. But im sure you have herd that one before.

 

Yea my volvo dealer is closed till monday, but I rented a code getter and I got: P0130 (Sensor Circut Malfunction"Bank 1 Sensor 1" and I also got P0303 (Cylinder 3 Misfire Detected). I got both of those codes twice to make four. What do you think about those?

Thanks

Skatermattc2

 

Still think Coils.
A bad coil will throw the O2 sensor code.

It wil be running to rich and wack the computer.

 

I got anxious wating for monday to come so I could by the coils and so I started playin around. I poped off the coil over cylinder three (the one that was misfiring), and I took off all the connections and blew them out with my mouth. Some dust flew out of the socked that fits over the spark plug. I pluged it back in and fasened everything tight and (nock on wood) the car has been running fine. No sputtering at stops!

I wrote the codes down and cleared the codes and the check engine light hasn't gone off this whole week. This is weird?? Do you think they might still be bad or could I have fixed my own problem?

Thanks
skatermattc2

 

See what happens I still think it is a bad coil.
You might have cleaned a connection or something that is helping now.

I have been there and done that as well.

 

Do the plugs too

 

I agree with the others, I think the coil is going to be the culprit.