He has 4 02 sensors - the OBD2 system measures the in and out reading on the cats. Test pipes will cause a CEL since there is no difference between the 1st 2 vs. rear 2 readings.
The path of least hassle is for him to stick w. his stock cats. Add down pipes & a cat back.
Bernie Bilskiberniebilski@cox.net 1995 Nissan 300ZX TwinTurbo in Cobalt Green 1997 Nissan 240SX SE in Ultra Red (some assembly required) 1995 Nissan Pick-Up XE in Super Black ZCCNV #390 ~ ECZA #368
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