02 sensor doug thorley header issue

[Beanzermin]

We installed a set of Doug Thorley Headers back in October. Bank 1 sensor 1 (the o2 on the drivers header itself) wiring did not reach the factory harness. We had to solder an extension onto the sensor. Not an easy task. the wiring doesn't take well to solder. so we had to clean the wires with flux first. About a month later the check engine light came on. It said there was an issue with that o2 sensor. So we bought another replacement. Extended the wires again. Its been 3 weeks (about 1600 miles) and the check engine light is back on. Now we are going to have to get a 3rd o2 sensor just to pass smog (reg & smog is due by the 29th). We are trying to figure out what the actual problem is or if there is a solution. Any one else have any issues? Doug Thorley claims the wiring should've reached. We are 8" too short...

 

[Beanzermin]

 

[lhommec13]

Many on this board have DT headers (myself included) and this is the first time I've heard of this issue. My guess is something must have gotten mixed up during the installation process. Otherwise, I'd think someone with the same problem would have responded by now.

 

[Spike555]

By adding solder to the wiring you are changing the ohms and that is causing your problems.
You need a O2 with longer factory wires.
A butt connector would work better to extend the wires and have less effect on the ohms of the wiring and you might get away with that.

Using the O2 you have, cut out the soldered sections of wire, use butt connectors and add new wire, see if the light stays off. Use heat shrink to waterproof the butt connectors.

Let us know if that works.

 

[hundyHAM]

By adding solder to the wiring you are changing the ohms and that is causing your problems.
You need a O2 with longer factory wires.
A butt connector would work better to extend the wires and have less effect on the ohms of the wiring and you might get away with that.

Using the O2 you have, cut out the soldered sections of wire, use butt connectors and add new wire, see if the light stays off. Use heat shrink to waterproof the butt connectors.

Let us know if that works.

Just to follow this... If O2 sensors are anything like thermal couples I've worked with in the past, you don't want to splice conductors. The computer expects ohms or volts to be within a specified range. Any deviation and the computer will read incorrectly and report errors.

Edit: tl;dr see if you can find a factory extension.

 

[Spike555]

Just to follow this... If O2 sensors are anything like thermal couples I've worked with in the past, you don't want to splice conductors. The computer expects ohms or volts to be within a specified range. Any deviation and the computer will read incorrectly and report errors.

Edit: tl;dr see if you can find a factory extension.

That is correct. If you can get close enough to the expected ohms or volts you will be fine, if you're to far off...
But we do not know the correct parameters so we cannot replicate them.
This is the same reason universal O2's do not work, you use your connector and splice in the universal O2's wiring, but then the parameters are wrong.