CEL's still on even after new sensor.

[silversol]

Car: 1999 honda civic LX

Mods: none, 100% stock

Miles: 140k

The cel was on so I pulled the codes and it would say that both the p[rimary anbd secondary O2 sensors were bad. So I bought new ones, replaced them, cleared the codes.

The cel came right back.

Same codes once again.

I have no idea what could be wrong.

I'm thinkoing maybe the cat is bad but I'm asking for others opinions, maybe you had a similar problem in the past.

[§treet_§peed]

how did you reset it to get them off? cause i know it takes longer if you didn't actually hook a computer up to it to have them erassed instead..i mean if you just unhooked the battery it takes longer to reset it....

[SLow_POke]

thats why u dont just replace sensors. Diagnos a problem b 4 u go swapping parts out.

Well sine your still getting the MIL there might a problem in your o2 wiring, ECU wiring, could be engine problems. I dont think itsd the cat or else you would get only the secondary O2 sensor CEL.

If any one you know has a GOOD scanner try and check LTFT (long turm fuel trim) . could be your running way to rich or Even LEAN and thst damaging the o2 sensor


but keeep it simple like mentioned above try RE-resetting it by removing the ECU fuse also leave it for a few mintues see what happens.


But im sure your problem is elsewhere post more info. gas mileage ect ect.




-Ernie

[3kgtdrvr]

^couldnt of said it better! +1 when it lets me again

[silversol]

The codes were cleared using a handheld OBD2 reader.

Car runs great, no problems besides the speedometer that doesnt show any speed.

[SLow_POke]

The codes were cleared using a handheld OBD2 reader.

Car runs great, no problems besides the speedometer that doesnt show any speed.

The best advise i can give you is take it to a Technician . A good shop that knows how to read sensor graphs. I use to use a Snap On "BRICK" (scanner) Gives you multiple inputs on all sensor. And If you knwo what a sensor should be doing(or looking like) you will find the problem.

liek i said dont replace the sensors unless your sure it is the problem. In this case i think you would have benefit from taking to a shop:yes: .

since sensors are a arm and a leg $$$.

im pretty sure hten u might have a engine problem, fuel system problem. liek i said b 4 ruinning to rich will damage your o2 and cat . the saem goes for runnig lean.








-Ernie

[SLow_POke]

:goodjob:
^couldnt of said it better! +1 when it lets me again:ninja:







-Ernie

[§treet_§peed]

:werd:

[milano pink]

try pulling it.... then unhooking your batt after switching your car to off.... keep the neg off for 15 seconds.... or just pull the fuse in the box next to it... 15amp fuse.. scond from the top right....might help you out

[3kgtdrvr]

all thats gonna do is clear the codes, not fix the problem. its just gonna come right back. and if u can pull the code then u can delete them with the scanner without disconecting the battery or ecm fuse. do what slow poke says and just take it to a shop...may i recomend
K&R Auto
670 old norcross road, suite 400
lawrenceville, ga 30045
(770) 339-0202
mon-fri 8-6 and sat 9-3

[2.0civic]

silversol, im working at the shop tomorrow if you want to come by and we'll check it out