sakasaku

Hey HT I was wondering what could cause a O2 sensor code and check engine light besides going bad?

My symptoms

If I start the car and go without warming up to the first line ill throw a check engine light and code 1.

And now since its go colder now it doesn't matter for some reason when m driving at a constant speed it will go to. I replaced it 3 monta ago and been doing this since the week after I replaced it help!!!

Malgerus

Check your wiring from the ECU to the O2 sensor. You're running a single wire 02?

sakasaku

Yeah are you saying at the ecu pin or were the I plug the o2 sensors into the clip?

sakasaku

?

4drEF

Need more info.
Is this the stock engine and preOBD ECU -or- has there been a conversion OBD1?

Are you running a header?

Did you check your wiring from the O2 sensor visually as well as electrically (continuity check)?

sakasaku

Sorry stock engine dual point d15b2 stock header obd0. I tested mila volts with key on its putting out 2 mv don't know what its suppose to be. Thanks



One other thing is the ecu is blinking once but can tell if its a slow for 10 or fast for 1 ???

project91crxsi

im having the exact same problem, but i have dc sport header also new o2 sensor so im too see if you get the problem fixed

4drEF

Slow blink stays on a little longer. Hard to check if you don't have any other codes, BUT code 10 is the IAT - very easy check! Go disconnect your IAT and see if you get another code.



Is is the ceramic header? Those are notorious for throwing O2 codes. The header disapates heat 'too' well and your 1-wire O2 doesn't heat up like it's supposed to. Try a stock manifold to prove it out. Wire up a 4 wire O2 for a fix.

project91crxsi

idk if its ceramic or not, how can i tell?

efjones9

try to reset ur ecu. i had a code one and replaced my o2 and forgot to clear the code. and had the same problem

sakasaku

ive reset mine but it happened for 3 months before i tried that so i think i ruined the O2 sensor

project91crxsi

yea i reset mine after a few days of getting a new one

efjones9

Get a voltmeter and use the positive lead to touch the o2 sensor. Wit until the car is warm tho. It should fulcuate between .08 or.09 volts or somewhere near there if it's below .07 then it's not getting warm enough. If higher than .10 then it's too warm. But u should be show obvious signs of it switchin between a lean and rich mixture

Red H VTEC

Try taking it out of the manifold and see if it still comes on while hanging in air.

project91crxsi

what will that prove?