2002 S60 Rough idle

[2MuchTexn]

I'm sorta new at this forum stuff but have found much great info in reading them. I have a 02 S60 I bought last November with 150,000 miles on it. I got it dirt cheap cause the people that owned it did not maintain the vehicle like they should have. I never owned a Volvo before but I learned how to replace the whole front end drive Struts, strut mounts, both CVs, all the bushings ect. A while back I had the ETM failure problem and had the Nashville volvo dealership replace it. All is well till that one started acting up and threw a Main bank 1 to lean code which resulted in me replacing the O2 sensor with a Denso for the cost of 214 bucks. That didn't clear up the problem though the check engine light did not come back on, So I took it back to the dealership and had them redo the ETM. It seems to be running better but I still have a problem with a idle that seems a little rough and there is a small hissing sound coming from the intake area. The dealership said that I need to have the oil trap cleaned out though i cranked it this morning and put the glove on the oil filler to see if it was building back pressure.......Heck no! It had a serious vac going on and tried to pull the glove down. I replaced the plugs a while back and have cleaned them since the first ETM failure and they all looked good. The idle is not surging up and down just seems to be running a little rough. As far as that hissing sound I am beginning to wonder if I might have a intake leak because it does seem to act as though there is a small vac leak in it.The dealership said that if I cleaned that trap I would probably solve the o2 sensor problem, but I think that has been solved and I don't want to take the intake off unless I absolutely have to. I have not noticed any oil leakage around the front of the engine and that glove check said it is open and working fine. What is your advice?

[2MuchTexn]

I went to looking for the hissing noise again and after a 10 minute warm up it turned into a whistle. Like the dealership said, it is coming from behind the intake manifold. I did spray a little brake cleaner down in that area and it seemed to make the idle run different which tells me it is a probably a hose leak on the famous PCV Breather System. I figure I will probably just replace the whole thing and new hoses. I understand sometimes they tend to pop out and the heat in that area is intense so after a while I am sure they get brittle and damaged. Thank you volvo for creating a pain in the backside instead of just engineering simplicity. I have already found the kit for 124 through another forum lead.

[jerseykat1]

all cars after (not sure what year exactly) a certain year sold in the US had to have PCV systems that were difficult for the owners to tamper with so that the vehicle owners would not be tempted to cheat there way through emissions inspection. You can blame the EPA/gov for that one not volvo. But it should be more durable.