I have a 99 volvo s70 glt with the 2.4l engine. I have recently replaced the pcv system, mass airflow sensor, all vacum lines, intercooler hoses with samco's hoses, air filter, turbo control valve, and the upstream and down stream 02 sensors. After doing this over a period of 4 month i still am have the same problem. When i start the car it seems like its getting choked the rpms jump from about 400 to 1500 rpm. Then when i'm driving it and come to a stop it dies but will start back up. It dosent do this all of the time sometimes it runnes like a champ, but when it acts up it really acts up. Does anybody have any advice. I think it might be the fuel pump relay or the fuel pump or the fuel filter is clogged, or the throttle body is going out but im not getting a code for that. I think the Throttle body has been changed before i got it because it has a yellow sticker on it. but dont know for shure

 

does it run rough only when it's cold?

 

no I live in Texas and have only have had the car for 4 months and it hasn't got cold yet

 

if mean when the car is cold it does it worst when the car is cold but only sometimes does it when it has warmed up

 

That car has an electronic throttle control. A lot of people have problems with those. You may want to have the dealer check that out.

 

I've had them check it out they told me it was the vaccum lines and the upstream and down stream 02 censor

 

What would be the outcome for the rough idle only when its cold?

 

I doubt you have bad O2 sensors if you are not getting a cel. You may have 1 vac line loose.