How do you tell if a oem header has cracked? Engine performane changes? Engine sound changes? Something else?
Listen carefully or have an experienced ear listen as well. A very average mechanic who just happened to be looking at my car curiosity wise, said, "You have an exhaust leak". He was right. Get a long tube of pipe insulation and use it as a stethoscope also. The shop that did change my headers out used that as well.
The only way to be sure is to do a smoke test. You will find out immediately if the header is cracked
You know. Some guy says, "I think you have a broken header." And you reply, "Are you serious or are you just blowing smoke up my butt? Seriously, you pump smoke through the exhaust and look for it to come out where it shouldn't.
[ame=http://www.youtube.com/watch?v=WtSTceRtIxs&feature=youtube_gdata_player]Exhaust leak testing using smoke - YouTube[/ame]
OK. Got it and it makes sense. Next question is who sells an inexpensive smoke generator? Don't recall seeing one at HF. I guess I can google it but what I am finding is either for smoking meats or DJ party equipment. I see some posts from various sources of people using the Party smoke machines.
Google "how to make a smoke tester". Basically a tin can, some hose, and a smouldering bit of rag inside. Oh, a compressor to add a bit of pressure to it.
