I recently put a turbo in my D16Y8 civic ex, and pieced it together from parts off ebay. The down pipe I bought was used from a drag kit and left me needing more slack from my o2 sensor. I went out and bought a new one, and spliced an extra foot onto the harness. This is a four wire bosh unit. Now I have a check engine light. I did this once before on my d16z6 motor from my 95 civic and didn't have a problem. Could it be that my Obd2 system doesn't like my turbo, or that i just ruined a perfectly good o2 sensor. The check engine light comes on immediately when started, not under boost. If I get the light out, I'll deal with the boost cel. Thanks, and if anyone knows where to buy an extension harness, you rule.

 

ttt

 

The problem is now that you've lengthened the wires...you have changed the resistance in them. This totally throws off the o2 sensor's reading and is why you're getting the error. I suggest you try and find some way around lengthening the wires.

 

thanks for the help, I'll see if there is some other way to fix the problem.

 

no, its because you need shielded wire for the o2

 

where could i pick up sheilded wire? radio shack or something? I didn't use it last time, I just used regular copper wire on my d16y8 and I had no prob. I must have been lucky

 

radio shack should have it

 

When i extended mine i just hacked up an old wiring harness and extended the wires and put a wire loom around it for a cleaner look. Ive had no problems

 

you should use shielded wire...

 

Did you extend the actual engine harness wires or the 02 sensor wires? And you checked the code to verify that it was the 02?

 

I believe you can call up DC Sport(as in DC headers etc.) and ask for an extension wire loom. They include the extension with some the headers they sell.

-Jeff C.

 

thanks for the dc plug info jcda6. I extended the actual wires to the o2 sensor. a nice brand new one to. I didn't check the code, but I didn't need to. That was the only thing I changed, and i wasn't throwing a code before. I could check the code though.

 

Why don't you just check the code for good measure. Stranger things have been known to happen.

 

Yeah, the code definitly needs to be checked. The turbo could be throwing something else, like MAP sensor.

the 02 sensor signal is 0-1v, so it is very sensitive to adjustments in resistance, and RF interference...

-PHiZ

 

ok, after I swap the wires to shielded wire, I'll check the code if I still have one. I doubt it was the map though because i put in the map check valve before i boosted and it didn't give me any problems, plus the cel kicks in as soon as I turn on the car. thanks for the help guys, I appreciate you taking the time to help.

 

My bosch gives me a CEl also. Just for fun, I swapped in 2 other OEM ones I had, and neither threw a code. But the Bosch one does. Could just be the sensor.

 

Yeah, sensor might be easiest thing to check, maybe in the handling it was messed up... It's easy enough to check... Swap it.
-PHiZ

 

I severely doubt you screwed up the sensor....I've seen the wires, and they LOOKED like normal unshielded wires. Even so, simply extending them would not change the resistance hardly at all, not NEAR enough to cause a code to be thrown.

I'd check the code first, it is more than likely something else.

 

OK guys, I just got in a used oem sensor in the mail and Im going to try to make that work. I also am going to get a obd2 code checker today at pepboys. its like 150. I couldn't find sheilded wire anywhere, so im just going to use wire from an old o2 sensor to extend the wires. I figure that has to be ok. I'll keep you all posted. Doing the job tonight.

 

If you got a brand new sensor, now is the time the extend the 02 sensor wires on the engine harness itself. If you pull back some of the loom where the 02 wires meet the plug, you'll notice that the sheilding terminates right where it starts to come out of the loom. Start extending from that point, and just plug the sensor in to the engine harness.

 

Thanks for all your help everyone. I got a scanner, and my code showed a malfunctioning o2 sensor heater. Turns out the bosh sensor was kind of screwy. Using extra wire from an old o2 sensor I extended a slightly used honda o2 and plugged the puppy in. NO CEL. car drives better than before and I can finnaly take that piece of tape off my dash to cover up the light. Thanks everyone.