Originally Posted by e39_touring

I finished up the install, and everything mated up just fine - no leaks! There was no way I could get a torque wrench on most of the header-to-head flange bolts, but I did add the missing studs and snugged all of them up the best I could.

I decided to delete the rear o2 sensors and use the supplied bung plugs. And, even though I was super-careful not to swap the front o2 sensor wires, somehow I did. The car would run rough and hunt for idle after warm-up. It's easy to tell in INPA if you swapped the wires, just run the lambda sensor test, and you'll see the values move on the wrong bank.

Overall, even though it's a tough install job, I couldn't be more pleased with the quality and fitment of the russian ebay headers - they bolted right up without trouble.

The CEL came on after about 5 miles of driving. I just got a spare ECM to mess with tuning. More on that later...

Sound - not much at idle. It sounds maybe slightly quieter than my old Z3 3.0 but with two tailpipes. At cruise, you can barely hear the exhaust from inside the car. It is a bit louder at higher RPM's during WOT.

Performance - I feel no difference in torque or at lower RPM's. From 3.5k on up, it feels peppier, and I'd say the +15hp or so dyno tests others have reported on e46fanatics seem to be spot-on.

Next up - ESS twin-screw supercharger?