now that the colder weather is approaching i notice my truck is having a hard time staying in closed loop and never at idle. i have read posts on a 4wire heated o2 sensor and mine is presently one wire. where do you connect the other 3 wires. also the engine has headers and the o2 ins on the 2.5" exhaust pipe 12" away from the collector flange, is this to far. where should it be located, on a cylinder tube or just before the collector flange. one more question. if the egr system is turned off does this affect your bpw from operating, i saw this on a post. 383 stroker, 64cc 23deg trickflow heads c/w edlebrock performer intake and adapter, cam is an extreme 4x4 comp. Cam. 12-235-2 grind ( .447/.462 lift, duration 210 218 lift @50, 111 lobe separation) . unit has hypr. Flattop floating pistons, eagle cast crank, 5.7eagle rods. 10.2:1 comp. Headers c/w 2.5” flowmaster exhaust. 16147060 pcm, $85def 454tbi 80lbinjectors

Use a 3 wire O2 sensor One wire goes to the original wire for the O2, One wire to a 12 power source that comes on when the car is on, and one connects to a ground. Can’t tell you what colors the wires are going to be because it matter which brand and type O2 sensor you buy.

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1989 Iroc-Z 5.7 350, Blue, T-Tops

Lightly Moded:
Edelbrock Headers, Rebuilt B&M 700R-4 Tranny, Higher Stall Torque Converter, Airfoil, K&N's, Ported Plenum
-- Blue LED Bakelite Dash & Climate Control
"Just some 17 Year old spending every dollar I make on my car."

A 3 wire will work just fine, usually they have 2 brown and a purple wire, the browns go to power, and ground, doesn't matter which one where, and the purple is signal to the ecm. Some brands use blk, and some white, in leiu of brown.

which is the best brand to buy, and thanks for the response gents.