Replacing my O/R H Pipe

[1968cyclone]

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.

 

[RedBullitt]

alright, for one, check those sensor connectors, upstream and downstream. when that light comes on, for safety it retards the timing and richens the fuel, making it sluggish. make sure the connections/plugs cant move and bang around on the exhaust or anything else, that will throw both of those codes. check your sensors if nothing is loose, they can go bad. mils wont do anything for those codes, they are the up stream sensors. you should pass if you can put a catted midpipe, unless you are in CA lol. im thinking there are mil eliminators on your car, or you would be throwing codes without those cats. if the sensors are loose, wire those babies down and you should be good. heck, you probably wont even have to change the mid pipe, if it is the problem with the connections moving around, a new midpipe wont help. check that out first, i would keep the catless midpipe

 

[1968cyclone]

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?

 

[RedBullitt]

i think it was, i had that problem on the passenger side up below the header, drove me nuts till i found that was it. umm the mil eliminators should go in between the sensor connector and the connector for the car. mine look like black tubes with plugs on both ends. it is possible to make them yourself and splice the wires, so yours could be different.