Okay the story is I just got this car, it's a 98 Civic with GSR running a chipped p28, the CEL always comes on after about 10-15 minutes of driving. I checked and it flashes really fast once for code one, which is O2 sensor 1. My question is why does it keep coming on? I installed an O2 sensor in the header last weekend because it previously didn't have one and I was getting bad gas mileage. Is there a way to reset it? And am I supposed to have two O2 sensors, the CEL is always for number one when I check it no matter which plug the O2 sensor is plugged into in the bay.

 

are you running a OBD1 harness or OBD2 harness?

 

2

 

are you using a obd2a to obd1 jumper harness?

 

your supposed to have 2 O2 sensors with a OBD2 harness. i've heard of a peice you can buy that plugs into the conector to trick the ECU but i forget what its called. try searching it. good luck

 

if ur using a chipped p28 then ur using a jumper harness which converts u to obd1 which means u dont need ur 2nd o2 which really doesnt help u i guess but i would try resetting ur computer and then seeing if it comes back on.

 

Did you install a NEW o2 sensor or a used one? Also was it oem or an aftermarket brand? I've read that with the Bosch, sometimes you get a bad one that stops working right away.

 

its a used one that came with the car

its was always plugged in but it was laying in the bay not in the exhaust system

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ThA IntegrA HI &raquo;</TD></TR><TR><TD CLASS="quote">its a used one that came with the car

its was always plugged in but it was laying in the bay not in the exhaust system</TD></TR></TABLE>

Maybe its bad, get a new one.

 

+1, it's probably a bad sensor.

 

k it seems to have gone away by it self. =]


got 60+ more miles to the tank too.