Replacing my O/R H Pipe

I recently bought a 2003 Mustang GT.

It has BBK Fulll length headers, BBK H Pipe and MAC Cat Backs. (sounds great if you are wondering.)

The SES light comes on occasionally - P0133/P0153. After some driving it goes away, then comes back. But away most of the time. Occasionally, the car runs like crap (like the fuel filter is clogged) for the first couple minutes of driving when the light is on.

I've been doing a bunch-o-reading here and I think I understand most of the issues.
- I'm not getting any codes for not having cat converters - either there are MIL eliminators, or I'm just lucky.
- The 133/153 codes may be caused by the fact that the front O2 sensors are in different than stock position
- Yes, I know I'm not legal

To make a short story long . ... I want to replace my O/R H-pipe with an H-pipe with cats. Which would leave me with:
- BBK full length headers
- BBK H pipe with cats (the new item)
- MAC cat back system

Does anyone think I will run into more SES light issues? Any problems with emissions inspections? Something I'm missing?


Any thoughts would be appreciated.

funny you should mention. . .

about the connectors banging around.

I noticed the wires/connectors flopping under th car. Like, they were dragginn almost on the ground. I tied them up - after that I got the codes.

but then I tightened them up - about a week ago - and no SES light since.

I'm just not sure if that was the problem - but could be.

The 'after cat' O2 sensors are plugged into the BBK mid-pipes. Does anyone know if they have built in MIL eliminators?