Headers and Slow switching 02 sensors

Mid length ZZP header on an LSJ, two new sensors still switching slow, is NOT the heater circuit I scoped it. Having switching speed of .2Hz at idle and .4hz while cruising, is somewhat better on the power a bit. I believe it to be sensor location, as far as I know the customer has had this problem the entire time he's had the car, which he got WITH this header on it. Off the top of my head I don't know the P code, but it is slow switching.

Would anyone argue the against the following and if so why?

I plan to either A grind down the huge Bung since it looks like it's simply too long.

Or, plug it and relocate the sensor further INTO the exhaust stream.

By the way, before you ask, I tried the sensors in question on another car with no problems. I also checked for leaks, and until I take the header off I don't know how it was welded. I have heard of problems with the mid length headers but this is my first car WITH it. Any insight is greatly appreciated.

Oh and tuning related, if the customer wants the code disabled would it still pass the readiness tests, I told him no because it's hard coded into the PCM, but I have never been in a situation to challenge that statement.

If they are long tube headers the delay will be caused by location. Some dyno headers have the sensor bungs located within 3-5" of the header flange. All lsj adjustments are made off of cylinder 1 due to the crank trigger location. If you move the sensor bung closer to the motor and put a flush tip o2 bung in then you will have more reliable readings. Closer location will result in a shorter delay time.

Check the flush mount bungs that am has. Even shows a short delay header mount install. http://www.aemelectronics.com/wideband-air-fuel-systems-15/4-channel-wideband-uego-controller-60/

It's the zzp midlength. I will post some before and after shots, I hit it with an IR thermometer the other day and was getting good temps I just don't think it's in the exhaust stream.