Hi guys, first post here, so go easy please. I have a '05 Outback Sport with a '05 RS engine swapped in. 85k on body, 56k on engine.
I had my check engine light come on the other day. Swung by O'Reillys to get ECU read. pulled a code for "Catalyst System Efficiency Below Threshold" (p04290). I've been told the CEL comes on when emissions is running at/below 95% efficiency. The guy at O'Reillys suggested running Seafoam since the age of the engine indicates that it's probably just gunked up, not requiring any replacements, and that I could just clear the code and see if it comes back. I got a can while I was there because I had planned to do seafoam regardless. Here are my questions:
1. Is seafoam a reasonable thing to try given my circumstances?
2. if so, should I just use the gas tank method, or feed the seafoam through a vacuum line as well?
3. here's where my noobness kicks in: I don't have an idea of which vacuum line to feed the seafoam through, nor where I would find any particular one. I've watched a few youtube videos but they are all for turbo models. It's dark now, but if it helps, I will post a photo of my engine tomorrow morning.
Thanks in advance guys.