“Really loud” sounds like an exhaust leak problem. PZEV Subarus do have cold idle faster than warm idle but it’s nothing unusual compared to other cars. And remember, exhaust has some smell, but it’s not from carbon monoxide - CO by itself is odorless, which is what makes it so dangerous.

 

That is what my dad thinks since I hadnt taken the heat shields off and the sound is still from up front it is possible there is a hole that seals after heating, as for CO I had no idea it was odorless but whatever I was smelling earlier is gone and its just PB blast left over that gave a small scare when it smoked a lot at the beginning but that has very quickly stopped and now its solely that the car is loud. Ill probably lift it up again soon and try to take the heatshields off to physically inspect the manifold. If that is the case and I need to replace it because a hole or gash is too large any ideas on where I can get something cheap but not going to cause issues in two years, especially if I preserve my current cat or simply get rid of it and sell it.

 

My 2007 Legacy (with PZEV engine) did the same thing, it was super-noisy as it heated up, almost like the valve train was coming loose and rattling around. I quieted mine down a bit with good quality synthetic oil (don’t want to add choices for this to the topic of the thread), but all the research I did at the time indicated it was just normal behavior.

 

I do have a rattling noise coming from the engine during acceleration and after dropping the manifold my heatshields may be loose so I will have to take those off and see while also checking for holes, but Ill try full synthetic I use penzoil high mileage at the moment. I also did research saying it was normal behavoir but still is really loud to me.

 

"loud" may need a YT video of this....NOTE that the EJ engines are notorious for piston slap....And that maybe the issue. But without hearing the sound....

 

Ill get a video and upload it tomorrow morning if all goes well is youtube preferable or can I upload it in an mp.4 or something similar

 

YT and then post a link.

 

I couldn’t get it as a normal format video but here it is as a short

 

IMHO, that's an exhaust problem....