3 wire o2 sensor

[AuroraGirl]

Most O2 sensor heaters draw 4 - 6 amps some as high as 7amps. If it were me I'd fuse it at 10amps, but you could try a 7.5 and move up to a 10 amp if you need it. It is acceptable to ground the heater to a good ground, but it does really need to be a good ground, not a good enough ground like you can get away with somethings. At the shop when wiring an O2 sensor I decide if the frame or body will be better, then solder and shrink wrap the ground wire to an eyelet. Grind a spot of bare metal, attach the eyelet with a bolt and paint over to seal.

some factory applications will ground to the exuast but then have a separate ground strap from the exhaust to the body/frame depending on application.

might be something to consider if the ehxaust is new or the space is tighter

 

[akchevrolet]

Alright well got that wired and the truck running and legal again. the shop that did the headers put the plug wires in the wrong firing order. I did the rest of the exhaust and there was leaks so it was running lean. that's fixed.