I am having to put cats back on the car. Currently I have BBK shorties and an O/R X-pipe. Also, I have a AFR gauge that I was looking into the instruction manual and it states to have the sensor for the gauge 18in from manifold but upstream from the cats. If I move the cats and downstream O2 sensors further from the manifolds would this cause any issues having cats that far downstream?
Thanks
Hi Zach Baumann,
No, there are 2 places under this chassis that was designed for cats to be placed......1 is where the OEM cats were & the 2nd is just after the 45* bend where the exhaust pipe starts following the bottom of the chassis & before you reach the trans crossover.........
So, you have 2 choices, you can either buy a complete catted mid pipe assembly such as this 1 that locates the cats just after the 45* bend in exhaust piping thus you have plenty of room to weld in as many O2 bungs as you want ahead of the cats:
2005-2009 Mustang GT PowerFlo-X Crossover Pipe with Cats - Full Assembly
www.slponline.com
Or you can buy 2 aftermarket straight flow cats (MagnaFlow has a very wide selection of these in either Fed-cert or CARB-cert) & have a certified muffler shop cut your existing O\R X-pipe & weld them in at the same section of the chassis as the above mentioned mid pipe shown then also weld in as many O2 sensor bungs ahead of the cats as you want as well.
Now any EPA legal issues derived from doing this will depend on where your car is registered at & the regs (CA would be the main area IMHO where the EPA "tampering regs" may get pushed due to wanting to weld in O2 bungs on option #1 or doing the entire thing on option #2 (why I suggested a certified muffler shop to do the work) even though there are several fully CA CARB-cert legal aftermarket weld in cats available (I'm currently running a pair of these myself under my Stang but I don't live in CA) that are CA legal thus 50-state legal to be used w\ these S197's, so just mentioning this so be aware.
Hope this helps.
PS--here's a picture of my setup where I had 2 Magnaflow #5461336 CARB-cert EO#D-193-140 TWC aftermarket cats welded in after getting the Kooks Hi Flow Race cats cut out in the very place I'm talking about..........no issues w\ cats working at all........even w\ LTH's, aftermarket non EPA-legal cams, aftermarket non EPA-legal TB, OEM IM w\ CMDP's installed & an OEM Ford Bullitt 83mm CAI that didn't come OEM on a GT thus is "non EPA-legal" & now w\ me doing all the tuning on it. Check out my last copy of a Forscan Mode 6 scan w\ IM Readiness report to see what I'm talking about (EVAP didn't complete due to gas tank being full when I pulled this out of my ECU after doing a KAM reset to put ECU into learning mode to run this check test just to see where all is at currently)................
