98 c70 trouble codes po302 and 4055

[kirk4]

I have an engine evap light on for months that read po4055. I took it to pep boys and they did a presurre test and said they found nothing and said it may be a malfunction in the computer. However, I feel they might have screwed me because they immediately started upselling me on new shocks and other stuff i did not and need so I wonder if they really did the test. Then yesterday I put the volvo in sport mode and let loose on the throttle once and my check enigine light started to blink. I checked it and it gave me a po302 misfire in cylinder 2. I could feel a little jerkyness early in the accel. but after the start it let loose good. The car has 101,500 miles on it and I have owned it since 85,000 miles. I am not an auto mechanic nor do I have alot of money so I am hoping this is not a pricey fix. Any help or thoughts would be much apreciated. Normaly I do not notice anything when in econo mode except every once in a while the engine will rumble or shutter akwardly for a second but is rare and never shut down and I never got a check engine light for that.

[Juan62]

For my 98 S70 T-5M: I had the same P0302 code and I change my spark plugs, reset the code, and test drove the car. If you decide to change your spark plugs, make sure they are (gapped) correctly and I would suggest Bosch or Volvo plugs.