02 sensor
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From: From Shelby Ohio,,Last 36yrs in Tucson Az
Car: 1987 IROC
Engine: 5.7 TPI
Transmission: 700R4
Axle/Gears: 9 bolt 3.27s
02 sensor
I wired up my 3 wire heated 02 sensor like it said here, and now im blowing the ecm fuse and wont start, its wired into A/C fuse cause its been removed. ant help? thanks
Joined: Dec 2004
Posts: 16,737
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From: Mile High Country !!!
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: 02 sensor
the heating element power wire can go to the grey wire on the fuel pump relay or to the acc power of the esc module pink/blk. Thread Starter
Junior Member
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Joined: Jun 2013
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From: From Shelby Ohio,,Last 36yrs in Tucson Az
Car: 1987 IROC
Engine: 5.7 TPI
Transmission: 700R4
Axle/Gears: 9 bolt 3.27s
Re: 02 sensor
I don't think I under stand, I wired one black to a switched ign ony,,i used a/c fuse for switched power since there is no A/C, one black wire ground on body, black wires off 02 and the blue off 02 to computer, purple wire. what id do wrong, I didn't mess with fuel pump relay.
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Joined: Jan 2000
Posts: 3,178
Likes: 48
From: Tracy, CA
Car: '87 IROC
Engine: LB9
Transmission: TH700R4
Re: 02 sensor
Unless there's something funky going on with your 12v (key on) source, I'd guess that there's something wrong with your O2 sensor if the fuse is blowing.
Again, post a link to the wiring instructions/schematic you followed.
Again, post a link to the wiring instructions/schematic you followed.
Thread Starter
Junior Member
iTrader: (3)
Joined: Jun 2013
Posts: 14
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From: From Shelby Ohio,,Last 36yrs in Tucson Az
Car: 1987 IROC
Engine: 5.7 TPI
Transmission: 700R4
Axle/Gears: 9 bolt 3.27s
Re: 02 sensor
ok . found the link with the diagram, it wasnt this site, but sethsthirdgen, but all concure that one blk wire was hot and one blk was ground. blue/purple was computer. 02 sensor is acdelco AFS74 from Rockauto. I beginning to think maybe this is something else. but all started when I wired up 02. it was a daily right up to this.
Re: 02 sensor
May be bad heating element in O2.May be shorted to ground internally in O2. I would check resistance of element leads (black wires). Sorry... don't have an ohm value range ..but you probably can research that and get its value.I would also meter both black wires to see if one black wire is already grounded internally as it may be polarity sensitive, meaning you can try switching black wires.






