I've got a 91 hatch with a jdmb16 with jdm dc sports 4 into 1 header , I got the motor as a package deal with motor, trans and computor. It has been acting up, backfiring and sputering when it wasn't at full throttle. I posted my prob and everyone told me it was 02 sensor. they told me unplug the sensor and see if the prob. quit. they said it would go into safe mode, but i could tell if that was the prob.


Well I unplugged the 02 sensor and the problem stopped which was cool but when I unplugged the sensor no check engine light, no codes, vtec still works and the rev.limmiter still works, How can this happen

 

just get a new 02 sensor

 

how come the car is not in safe mode and there are no codes thrown with the sensor unplugged

 

There should be two o2's on that motor.

 

there was but those headers only have one bung so we jumped the secondary sensor into the primary which worked somewhat untill all the sputtering problems so then I unplugged it completly, expecting it to throw a code and go into safe mode, but it did'nt happen

 

that's most likely your problem right there - the two o2 sensors most likely can't be wired in together - you will either need to convert to a 4 wire o2 sensor, which i don't remember how that can be done, but it can be, or put the two o2 sensors back to two, and just get the other one put in - you can get the o2 sensor nut and have it welded to your header for the second sensor. and i believe to read the error codes on the computer that you are running for that car, you need to actually ground a certain wire, then the light will flash on the ecu. i know in my hatch with the obdI computer and everything i am running, the check engine light comes on when there is a code, but as soon as i turn the key off the light goes out. maybe your check engine light just isn't coming on. check the ecu for codes anyway.

 

It will likely come up soon. Here is what you must do. Send the header to the muffler shop where they can weld 2 bungs in the factory b16a locations. Then wire the o2's like this

 

but if it still runs great with none plugged in would it hurt to run with none

 

same idea, aftermarket 4-2-1 header

 

from what i understand, running with the o2 sensor plugged in makes the ECU run in open loop mode all the time.. atleast on PM6 it does.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by crx_88_si &raquo;</TD></TR><TR><TD CLASS="quote">

same idea, aftermarket 4-2-1 header</TD></TR></TABLE>

i would do like the pic and get a second location for the second o2 sensor. I know when one sensor say cyls 1-2 run lean it will cause the cyls. 3-4 to run rich, and vice versa.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BNiceB16 &raquo;</TD></TR><TR><TD CLASS="quote">but if it still runs great with none plugged in would it hurt to run with none </TD></TR></TABLE>

Ya, cause even if it runs good, it will still run too rich or too lean. Ryan