I just spent about 24 hours installing tog headers on my 04 Mc ss I am not an experienced mechanic. But I figured it out. They are on. And they sound amazing.... but... now the car runs terrible. And keeps dying, at first it was idling at about 2k rpm. Then I remembered I forgot to put the o2 sensor in the bottom header and plug it in. After doing that it keeps bogging down and dying unless I give it gas. It will drive just fine. But it won’t stay on at idle. I have no idea what’s going on. Because this is my first attempt at modding. And I only undertook the mod because I got the headers and exhaust off a heavily modded 99 gtp with a wiring issue(melted wiring harness) I bought for 500 bucks. I don’t have a code reader and my budget is very low. Someone told me it could be due to an air leak on one of the headers.