I have some headers also, and you get a CEL because there is no cat between the o2 sensors.
What I did was I took my second o2 sensor off the clip, and I cut the wires and lengthened it about 2.5 - 3 feet (just a guess) with 14 gauge wire.
Then you put a high flow cat on where your second cat was, or your test pipe (if you used it)
In your mid-pipe after the high flow cat, you put an o2 bung. run the lengthened wires along the brake lines or gas lines, and zip tie, and put the o2 sensor in the bung.
The ecu now should read a cat, and the CEL will go off after you disconnect the (-) battery wire to clear and reset the ECU codes.
I'll just post in your thread, since we both just installed OBX headers and are having similar issues. I'm actually getting a bung installed after my new Carsound cat tomorrow, and probably getting ripped off, but oh well.
Tibmeister has said in his posts that you don't need to extend the O2 sensor wires. Has anyone else successfully installed their O2 sensors without extending them? Here are two posts by Tibmeister:
Quote:
[body]
FYI-----don't cut any wires when installing your headers. All you have to do is to unwrap the plastic wire loom and pull out the o2 sensor wires and run it behind the motor( or under the intake manifold). It's just a perfect install.
And for the 2nd o2 sensor, pull out the shifter plate and untie the sensor wire and pull it out from underneath and install the O2 sensor. but then again my cat came with the bung already.
-------------
All you have to do is to take the wire loom off the harness and pull out the O2 wires all the way to the ignition coil and re- wrap it with tape and if you want some loom. It will reach down to the first O2 bung. for the second sensor, the O2 sensor on the cat that I bought just screwed right in. If you have to extend it, just pull out the shifter plate and the stereo plate and inside there is a harness that is tied up. it's black and it has a grommet leading to the cat. un-tie and pull. but you really shouldn't have to. I'll take a picture of the harness once it gets nicer here.[/body]
I completely unwrapped the first O2 sensor wires, and it still doesn't reach the bung in the 2nd section of my OBX header for the first O2 sensor. I see no extra wire anywhere. Rerouting behind the engine still doesn't give enough slack.
For the second O2 sensor, I traced the wire up to the top of the firewall, where it looks like it goes into the firewall. But I removed the shifter baseplate and didn't see any wiring beneath it. There was wiring on the inside left, a yellow loom, but it didin't look like it was connected to the O2 sensor.
I don't see how you can do this without lengthening the wires on a 2000 Tib. If anyone has any suggestions I would love to hear them. Otherwise I'm going to add a few feet to each sensor. I hope this doesn't cause a CEL like others have supposedly gotten after they extended the wires. A CEL will fail me on inspection.
Well, I didn't extend the first O2 wires after all, but it's not ideally routed. I have it running behind the engine now and it just reaches, and that was after removing as much loom as I could.
I extended the second O2 wires by two feet, cutting the plug on the sensor and not the one on the harness. This was probably a mistake, since my CEL just came on. According to a TSB on Webtech:
Quote:
O2 sensors use the wiring/connector for the “reference air” used in determining
the O2 signal.
WARNING: Do not use connector grease on O2 sensor connectors. The grease
may cause electrical connection problems.
I'm guessing that by extending and soldering the wires between the plug and the sensor I killed its ability to check for reference air. I should have extended from the harness side. Hopefully I can correct this. Before I redo everything I'm going to try removing the soldered connection from just the reference wire. If I can figure out which one that is anyway.
This has been covered so many times I'm surprised the right post hasn't been stickied and everyone else physically and verbally abused. Do not solder the reference wire. Use an obd2 compliant high flow cat and place the 2nd o2 sensor after that cat. Do not ask why in this thread it has been covered in detail in others here.
You can call me an ass all you want, but I'm not sporting a CEL.
Originally posted by rbuecker
[body]
Do not solder the reference wire. Use an obd2 compliant high flow cat and place the 2nd o2 sensor after that cat. Do not ask why in this thread it has been covered in detail in others here.
You can call me an ass all you want, but I'm not sporting a CEL.
[/body]
I'm not going to call you an ass, but I am going to tell you to read my post entirely before you spout useless advice. I have an obd2 compliant high flow cat, and I placed the 2nd o2 sensor after that cat as stated above. I don't need to ask why because there are at least 100 threads here that explain it, and I've read every one. Hell, I even quoted the reason why above. Read before you reply. And like I said, I'm going to remove the solder from the reference wire and just crimp. Although I am suprised that I got a CEL, since many other people here have soldered the reference wire without getting one. I'm guessing they extended from the harness side of the plug though.
I think I still might get a CEL even if I do just crimp the reference wire, since I extended the plug 2' away from the sensor, and that's where it gets the fresh air from. And there could still be enough of a voltage drop to give me a CEL with a 2' extention on the sensor side. I will probably switch the extension over to the harness side, so that the plug is right at the sensor instead.
Alrighty! Yeah, it has been covered a lot. I always search first so I don't look like...an ass. Because there definitely have been a lot of threads on CEL after header install.
I won't be removing my solder any time soon after all. My CEL originally came on the second time I started my car, and had been on every time since then, but I had only driven 25 miles.
Today I drove 100 miles, and two amazing things happened. First, my new exhaust setup (OBX header + Carsound cat + 25" thrush glasspack + Dynomax Superturbo muffler + 2.25" mandrel bent pipe) went from loud and full of resonance in the cabin to a low growl with just a slight drone at 3000rpm. Second, the CEL went off about 90 miles into my trip. Wow. Maybe the cat just needed to break in? I've restarted the car several times and driven it hard, really flooring it, and it hasn't come back on. I guess I should get my OBDII codes checked though.
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CEL after installing headers
Because there definitely have been a lot of threads on CEL after header install.
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