I see people buying these for longtube installs, but figured its pretty simple to just make your own. I did that and now am throwing codes- O2 sensor malfunction and O2 sensor heater circuit malfunction. Is there something special in the wiring here, or did i just not use thick enough guage wire??


Thanks,

Mike

 

when you say extension did you splice and extend the wires on the o2 sensor itself? If you did this, that is your problem. Believe it or not, the o2 sensors references the oxygen content of the air in the wires. This is documented in the service manual. Also check the LT1_edit mailing list archives it has been documented there as well

 

I unplugged it, cut it in the middle, and added wire. I didn't open the sensor or anything.

 

For decent results, I believe your going to have to use the same wire for splicing as the O2 has in stock form. I tried doing this myself and the O2 did not read accurately afterwards, and had to go to an open loop program (dyno was a day or two later).

 

Any idea on what type of wire it is??

 

The 02 sensors are unfortunately no good. Replace them and this time extend the factory harness leading to the sensors or ante up for the extenders. there is nothing particularly special about the wire other than the 02 sensor references the air contained in them. It may sound like BS but that is the way it works.

 

hrm

So i can cut the factory wire before the plug? If so perfect, i have another set laying around.

Very strange though.

 

You have to leave the factory 02's intact. No cutting or hacking what so ever. You must cut and extend the 4 wires from the engine harness.

 

Can i ask you where you got that info?

I've got the passenger side spliced with a loner wire and at first it started reading .000 and you bump the wire and it would read .450

Now it reads a solid 1.025mv i have no idea whats going on, I spend so much time on others cars i haven't really looked into it yet. I just have been runnig a open loop tune.

I'm thinking though that the hookers have burnt threw my harness.

 

It's there, take my word for it, or not. If you cut the 02 wires directly connected to the 02 sensor you will have problems. Been there, done that, went through $100 in 02 sensors to learn what I am telling you now.

 

Thanks for the info on this one guys!!! I am having fits with o2's (currently running in open loop ) and i just remembered my dumbass mechanic said that he "had to make a couple wires longer" im sure he screwed that up among other things.....lol

 

So you can lengthen the engine harness but not the actual 0 2 sensor wire?

 

that is correct.

 

And just remember that the terminations have to be made with the utmost care. The O2 sensor ouput is approx +550/- 450 millivolts, riding on a 450mV signal from the PCM. You are dealing in very tiny voltage changes, so a huge resistance from a poor termination or splice is going to cause major accuracy problems.

You also need to look at how you route the wires. Getting them too close, over extended lengths, to the high voltage ignition wires can induce spurious voltages in the O2 sensor circuits and foul things up. There's no reason for a person capable of doing the right quality work to buy ready-made extensions. But if you don't know what you are doing, ready-made extensions may be the cleanest approach.

 

So how would one go about fixing a hacked up o2 sensor wires? I'm decent at wiring however i am tired of dealing with it and want it to be right! Can you buy the whole assembly somewhere? Thanks guys...