Guessing you have a catless up pipe on the car already ?
Most level it in the old up pipe, you should be able to get it out with a wrench and some PB Blaster.
Do you have the 2.2k ohm resistor to defeat the CEL ?
174,000+ miles, 5/20/12 new ej257 short block, 8/20/11 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. Also CHECK YOUR OIL, these cars use it.