99 s80 t6 138xxx
 

So my s80 started to slowly rev high while in park, them it slow down to normal after a few seconds. I read previous threads and i seen that id have to clean out the throttle body. Would it make sense to clean it or just replace it? Im doing a tune up on it so i was going to add that to my list. Also my check engine light is on and the code is for a emissions leak, so i changed the gas cap and the light came back on. I then changed the evap purge valve and the light came back on. The dealer said they would have to do a smoke test to see what the issue is but i figure out what else the problem is. Any idea what that might be?

not sure if this would throw a code, but yesterday I was going through the process of changing the breather box on my
and I noticed that some of the rubber hoses were cracked/basically rotting. Not sure if that's why you're throwing an emissions leak code- but my 99' t6 s80 also has a emissions light,

if you decide to look at the pcv system, -- this is an s60, but the process is ALMOST identical except for a few things. If nothing else, look at 6:50m, when he has the box off- you can see how the bottom is completely stopped up. Not sure if these just have to be bought new or if they can be reused. Trying to find out.
Also the blockage test at 7:29,whether the system is clogged in the engine-
and the small fitting that is clogged @ 8:30.

Robert from the first video says if there's no record of someone servicing that , then you probably should do it since it can cause leaks /failures of the cam seals & the MAIN SEAL! due to pressure building up since the air cannot escape/ circulate.

I would start with a thorough cleaning of the throttle body. This procedure will require removing the throttle body, unplugging it, putting it on the bench and cleaning both sides.

Then, reinstall and see how it idles. A plugged crankcase breather can allow backpressure to get into the incoming air stream and confuse the computer since more air is entering the engine than the air mass meter can account for.

Thanks guys ill try these methods out.

Hey man I had this same issue with an s60. I cleaned the throttle body and it did not fix the issue. I spoke with many people who told me that I need to get a new throttle body. AND I cannot get a throttle body without taking it to the dealership to "program" that new throttle body.

This is what I did that solved the problem completely. I went to a junkyard and took a throttle body off of a similar year'd volvo (I had an 2001 s60 and got one from a 2000 xc70 i think) and put it on my s60 and it worked and has worked for about a year straight now.

Good luck!