My manifold was cracked so I priced it and it was about 900$ canadian. So I figured that I would bye headers and a cadalic converter seperate to save some money. By doing this, I had to extend my secondary O2 sensor wires about 3 feet. Now my engine light ls going on. The OBG2 says that it's my secondary oxigen sensor. So I replaced it. Still comes on so I changed the primary oxigen sensor and it still goes on. I have a new air filter, rotor and cap, never touched the timing and don't know what else to do.
I have a 98 Civic EX (LX for the US) and the manifold and cadalic is in one piece.

...After I reset the engine light, my car runs really rough until my engine light goes back on into limp mode then it runs better but still is hard on gas. One more thing, when I extended my wires, I didn't disconnect my battery and the wires rubbed against each other and sparked a little. Could this have screwed up my ECU??

Highly appreciate some help!!

Modified by Red Andy at 2:22 PM 2/5/2005


Modified by Red Andy at 2:23 PM 2/5/2005

 

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

...One more thing, when I extended my wires, I didn't disconnect my battery and the wires rubbed against each other and sparked a little. Could this have screwed up my ECU??

Highly appreciate some help!!
</TD></TR></TABLE>

I think that very well could be the cause, if you made sure to connect the o2 sensor like it was before I would think this is the cause. Do any of your friends have a civic of your age? if they do it's not very hard to just try swapping ecu's and seeing if the problem goes away, make sure the wires aren't still shorting though or you'll have to junk ecu's.

 

My sister in law has the exact same car but it is a standard. Would this be the same ECU??

 

No, you cant use a manual ECU on an auto car, at least I dont think you could.

Also check the wiring of the O2 sensor, maybe you crossed a wire?

 

I tripled checked the wiring and it's all good.

 

I'm not sure but I think you can use an auto ecu on a manuel but that you would just throw a code b/c of the diff. trannys. I would dble chk these though.

Good Day,
RH.

PS. I always disconnect my battery when working with electrical shyt ! ALWAYS !

 

I'll never do that mistake again. Is there a way to check the ECU istead of swapping it with another??

 

Im not sure if this is going to be of any help but....did you put the catalytic converter back on the car? because if not both oxygen sensors will read the same thing,the computer will think the cat isn't working and it will throw a code. There HAS to be a working cat between the oxygen sensors in most cars with obd2 although some newer cars actually have an oxygen sensor in the middle of the cat hope I was of some help....if not sorry I will STFU now good luck man Nick~

 

The original manifold and cat is in one piece. I swaped it with a 4-2-1 header then a new universal catalic afterwards. Primary o2 sensor is on the header and the secondary is after the cat.