Richie66
New Member
I bought a 2004 GenIII 5.7L crate motor in early 2005 for a kit car I built. The engine harness I also ordered from Ballarat Holden at the time. The harness only ever had two 02 plugs on it, both flat 4-wire type - I connected these to the pre-cat side on the exhaust system. The car was set up to pass emissions etc and was licensed no problem. However, I have since read there should be four 02 plugs on a harness typically, two pre-cat, two-post cat, in addition the pre-cat plugs are supposed to be square type (not flat) to avoid an incorrect set up either side of the cat. Can anyone confirm I do have the correct harness / 02 sensor set up.