I was looking at flowmaster freeflow cats that operate without the smog pump and was wondering if anyone has had experience using these or other non air pump cats to pass e-check, getting the air pump and all the hardware for my 1992 gt has been less than fun as most of this stuff isn't even in the junkyard anymore. If I can get an H-pipe and weld in two of these instead that would be awesome. Thanks for any help.