I am new to the forum so pleaseexcuse me if this question has been repeated. I own a 01 volvo s60 2.4t that i got a few months agoand lately i hav had a problem with it misfiring, hesitating, and SURGING. the check engine light has come on a few times and it has blinked once. I dont know if its the MAF or some sort of softwareproblem, but it has recieved the throttle body upgrade. It acts like it needs new plugs and wires but the plugs are fairly new on the car.

 

Sounds like you might have a bad coilpack.

 

would that cause the surging as well?

 

The misfiring might cause as well.

 

It hassurged for awhile and thenthis just started happening. I thoughtthe surging might have been from the pcv valveand trap not being ableto "breathe." Ill try it out though. is it recommended to replace all of them at the same time or can u just replace the one that has gone bad. Thanks for your help.

 

I would replace all the prevent you from pulling it all back apart again soon to replace another one.
The vent system could also make it surge you might want to check the system.