Ok, the car is a 95 CX with a B20B motor. Stock. CX engine wiring harness.
The program we're running on Crome is a P28 program with more fuel, and disabled VTEC.
I know the CX has a 1 wire O2, so on the Crome we disabled the O2 and the heater. Worked fine for a few minutes, then it started throwing a code for O2. Then we tried an Uberdata program, and the same ****.
So I wired up the O2 to a full 4-wire, and still.. same ****. Within 5-10 minutes of running, it gets a code 1 and code 41, and starts bogging down like crazy, as if it were misfiring on one or more cylinders.
I've gone through the diagnostic procedure outlined in the service manual to a T, and everything checks out fine until the last step, and it only gives me two options.. replace the ECM or replace the O2. I have tired four different O2 sensors, and two different ECMs.

I'm switching it out to an Integra LS engine wiring harness on monday, and hopefully the problem will be gone, since it will be all OEM wiring.. but I was just looking for some insight on this problem. Thanks.

EDIT: We switched the program to a P72 base map. Check engine light still comes on intermittently, but now it only bogs at light load(i.e. cruising on the freeway), and under WOT it seems fine... but I still would like to have this CEL gone. Anyone got a clue?





Modified by Mike K at 1:52 PM 1/29/2006

 

u disabled the O2 sensor and O2 heater in CROME/UBERDATA? if ur still getting a CEL then the ecu is still not seeing a signal at the ecu side. a quick fix to get rid of this problem is to just run a 1 volt signal to Pin D14 by the ecu. this is the O2 sensor wire. doing this should get rid of the code with the closed loop and heater STILL disabled in crome or uberdata.

do u have a wideband hooked up to the car to tune the fuel maps? u said u added fuel to the map. the stock fuel maps will usually run the car pretty rich. u should have left the STOCK basemap for the P72 in there. the bogging u are experiencing might be due to the car running too rich. change ur spark plugs too cuz they might be fouled out

 

we added fuel because the spark plugs were almost white. running lean for sure. we didn't have a wideband hooked up, but as light colored as those plugs were.. we could tell it was lean.

ok, i understand what you're saying, since the ECU is not seeing a signal @ pin D14.. but it IS. i wired up the 4 wire O2 sensor properly. the stock CX 1 wire is the O2 signal, then I added a pin @ the engine wire harness side to the ORG/BLK wire on the strut tower, which is heater signal. then i added power and ground accordingly.

what i am wondering is, if we disabled the O2, it shouldn't be looking for the signal at all, right? so i could just unplug the sensor if i wanted to, and since it was disabled.. it shouldn't throw a code. am i right? or does it work differently?

 

What code #?

With the o2 sensor and o2 heater disabled in Crome it will not set a MIL for the o2 sensor/heater, even if it is not hooked up. Check your map and remove the checksum routine.

 

it will throw a CEL still even if no sensor is hooked up. it wont throw a code right away but it will thro it once in a while. when i didnt have my sensor connected it did not throw a code after i drove it for like 1 week. then it throw a CEL code 1. shutthe car off and turned it back on and the code went away. its a common problem with crome,uberdata, hondata. no biggie.


at idle if the plugs were white then that will be normal. u need to check to see if the plugs are white after a full throttle pass (after u make a full throttle pass, turn the engine off and pull to the side of the rod. dont let the car come down in rpm by itself. if u redline at 8200, try to shut the car down at 8000 rpms)

 

i know the plugs should be near white @ idle. the car was on a hoist, and it was in gear, revving to about 5000rpm holding.. then shut it off... they were still white. i realize this isn't the same load on the engine as if riding @ 40mph or whatever.. but it is SOME load. and the motor IS lean.

either way, does anyone have an explaination why it still throws a code for O2 even though it's been disabled? since the ECU isn't looking for it, there is no reason the code should come up.

 

So they rev'd to 5k, held it for a bit, then turned the key off? It needs to be done on the road, with higher rpm (the critical area), then instantly shut off before you lift the gas pedal. Just a second of revs bouncing or being held will change the outcome.

 

problem fixed. loose pin fit @ A6. heater control circuit. installed a new pin and applied some lithium grease for good measure. no more CEL.