projectEK9

I recently changed my exhaust manifold and secondary o2 sensor. Both parts were purchased used from h-t members. To my knowlege they were still good but thats not my concern. Enough of the background info....

My original secondary o2 sensor was cracked near the top of the wire due to no slack while being plugged in to the harness. After we changed the exhaust manifold and replaced the secondary o2 sensor it wouldnt reach the harness so my friend cut some wires from the old secondary o2 sensor and extended the wires for the new secondary sensor. Everything plugged up fine, I reset the battery to clear the CEL code, fired the car up and the CEL light came back on!
I pulled the code from my ECU and it came up as code 65, Secondary o2 sensor heater.

What should I do?
Get a new secondary o2 sensor?
Try another used one?

HELP!!! I need to take my car to smog at the end of the month.
I havent driven a whole tank of gas to see if my gas mileage is improved but so far it looks like its improved alot.


edit* This brings me to another question.

Are all 4 wire o2 sensors interchangable between cars?

projectEK9

bump

EX-T

Get on ebay and do a search for an O2 simulator. It's a $10 fix and will not harm your car in anyway!

EE_Chris

Buy a meter and a Helms and follow the troubleshooting steps. The O2 heater resistance is spec'd between 15-40 ohms.

Its gonna get spendy replacing parts when in fact it might be your wiring harness that's duffed.

projectEK9

The thing is my car was working fine before the cat swap. I hope its not the wiring harness.

EE_Chris

Hope doesn't solve problems, nor does guessing.

Your call - replace it, diagnose it, or hope it fixes itself.

When your friend cut the wires - did he re-solder or just twist and tape?

projectEK9

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EE_Chris &raquo;</TD></TR><TR><TD CLASS="quote">

When your friend cut the wires - did he re-solder or just twist and tape?</TD></TR></TABLE>

Soldered it

EE_Chris

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by projectEK9 &raquo;</TD></TR><TR><TD CLASS="quote">Soldered it</TD></TR></TABLE>

Well damn, that just killed hope, didn't it?

Time for a meter.

projectEK9

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EE_Chris &raquo;</TD></TR><TR><TD CLASS="quote">

Well damn, that just killed hope, didn't it?

Time for a meter.</TD></TR></TABLE>


When you say meter do you mean a obd2 scanner?

EE_Chris

An OBD2 scanner is for reading codes - some of them may give live sensor data but this has nothing to do with the code you have. The meter that I am talking about is a multi-meter - it can measure voltages, resistances and some of them can measure current.

The most basic of meters can at least measure voltage and resistance and that alone accounts for like 90-95% of the troubleshooting steps within the Helms.

projectEK9

Cool thanks alot EE_Chris

projectEK9

Im going to buy a multi meter today but lets just say when I plug it into the harness it doesnt show enough power/ no power. How would I fix a bad harness? Would it mean buying a new one?

EE_Chris

See, this is where a Helms comes in handy. It leads you through the troubleshooting steps and then tells you what needs to be checked/repaired in order to fix things.

No, you wouldn't have to buy a new harness - just repair what is broken. If a wire is shorted to ground, more than likely its because the wire has rubbed up against a sharp metal object (which is grouned) so to fix it, insulate it. If the wire was broken, solder it back up and shrink wrap.

But again, measure the resistance of the O2 heater section (you can do this in your living room) to make sure all is well there. You do that step before you ever get to touch the wiring side of things.