1992 si d16z6

i just got my car back from being stolen
i had to replace my ecu i got one from a 95 ex manual
but now everytime i start the car im getting a cel which i never had gotten before
i changed out the sensor and still got the same thing
when i take out the back up fuse or unplug the ecu and start the car the cel comes on within like 5 seconds
isnt that way too fast to come on for an o2 sensor? could it be a fuse im not sure which fuse it could be

 

Hi there.Did you replace the sensor yourself or did you take it to a shop.You say its error 41 the o2 sensor heater right.On some Hondas there is 2 of those sensor there is 1 on top and 1 at the bottom of the heat shield on the manifold.Do your car have 1 or 2 of those sensors?

 

Also want to ask when you drive the car does it run smooth or does it stall and stutter?

 

92-95 Civics will only have 1 O2 sensor, djedd.

OP, do you have a voltmeter? Sounds like it's time to test wires for continuity, see if any of them have been damaged by the thieves.

 

You have the service manual, right?

 

yes i just never had an issue with my other computer unless my other ecu was bad idk and i tried 2 different ecus and 2 different o2 sensors and the code always comes on within 5 seconds
usually it would take a few mins to throw a o2 code i thought

i guess ill test the wires but what fuses should i check?
i wish it had an obd2 port to see whats going on

 

I had that problem with my 93 del sol si with D16z6. After I replaced the O2 sensor I still had the light.

The problem turned out to be a hairline crack in the exhaust manifold in the runner just behind the O2 sensor. Even with the heat shield off you couldn't see the crack. The crack caused the O2 sensor to read a lean condition.

I replaced the exhaust manifold with a ebay header.

I heard a cracked exhaust manifold in that particular area is common.

 

could be but i have a99-00 tubular y8 manifold on there

 

Still worth checking for leaks, while you're checking the wires for breaks.

 

ok with the key on one of the wires is getting 12 volts
i also put a test light on the ground and posative and it lights up so everything is good
somthings not right

 

just got a brand new denso sensor and the same thing happend cel 41 came on within 3 seconds

 

Why are you ignoring the troubleshooting well described in the service manual, again?

 

ok when i change the ecu to a different one my friend gave me from an auto the only code is 19 which is the auto trans lookup somthing and no code 42 just 19 so could it be the ecu is the issue??

 

ron i tested everything what are u talking about?

 

I would guess something is wrong with the original ECU because like you said the cel is coming on too fast. I think a good ECU runs open loop until the engine reaches operating temp than it would show a cel for a bad O2 sensor if necessary. If you pull the ECU fuse to clear the memory and then restart the engine does the light still come on real fast? These ECU's capacitors can fail in odd ways and cause odd circumstances.

 

There are four wires for you to test. You only tested 2.

 

yea it comes on very fast when i reset the ecu
theres a way to test it but it says i need a test harness
i had to buy this ecu off craigslist because the thieves took my origional one

 

You don't need a test harness. Just backprobe with a voltmeter.

 

Cel code 19 = Automatic transmission lockup control valve.

 

how would i backprobe it all it says on the service manual is to use a test harness

 

stick one probe in a23 and stick the other probe into a6, whats the reading

 

with everything plugged in the ecu and they key on

also did u mean a 26?

 

sorry i should of put this page up too

 

it says that if i unplug the a connector and if im getting power to the o2 harness then i have a short? is that true?

 

ok so i bought another p28 yesterday plugged it in and no code so i guess it was the ecu

the one on the left is the new one with no code and the one on the right is the one that throws the cel 41

now for some reason the sticker was peeled off the side of the new one on the left but if u open it it says a00 so thats good but im just wondering if any of these look tampered with because on the new one on the left the casings are different