This is for my neighbors vehicle. It's giveing code 327. We've replace the egr and the electronic vacuum thingy. I figured maybe the O2 was playing games with the egr so we found a place that carried 1 of the o2's (he has 2 upstream and 1 down from what i remember). Any idea's?

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89 IROC-Z 350 TPI

-Flowmaster Catback
-Performance Resource Chip
-700R4 (Rebuilt) Too much done to actually list
-K&N Airfilters
-Ported Plenum
-2.77 Gears (not much to brag about but eh, its there)
-MSD 8.5 mm plug wires
-Gutted cat
-!AIR
-Gutted Air Boxes