TheHooded_Mike

I have had a "Secondary O2 Sensor" CEL for awhile now, but haven't bothered to fix it until today (doesn't affect anything) because I need to do an emissions check soon. So I put a new one on, and still have the CEL after an ecm reset.

Could this be another bad sensor? What other possibilities are there?! Thanks...

dannis.

try seeing what codes its throwing.

TheHooded_Mike

Ya I guess I'll have to do that to see if it's still the same code or not. What a pain in the ***.

pdiggitydogg

if you got a crappy parts store bosch sensor it could be bad, or you rewired it wrong if universal

TheHooded_Mike

It's a direct-fit NGK from JCWhitney...I was thinking I might've gotten a bad one though. How do I check a code again (OBD2), I forget? Last time I had someone plug in a code reader.

pdiggitydogg

possibly a bad sensor...but that would surprise me from denso


https://honda-tech.com/zerothread/1901557

TheHooded_Mike

Thanks alot for the link. I was looking for a no-BS post on checking the codes and yours is just great.

TheHooded_Mike

Ok, I pulled codes 41 and 65. "Primary oxygen sensor heater" and Secondary oxygen sensor heater wire (black wires)". Does that refer to the primary sensor and secondary wires?? Help please!

EE_Chris

It refers to heater section in BOTH of your O2 sensors. However, you're more than likely looking for a blown fuse. Under the dash, the alternator SP fuse (15a) - take a look at it.

Is the car stock?

TheHooded_Mike

The car has a catback and an intake...and it's an ek (just imed you back). I don't see that fuse, and now that fuse box cover won't stay up. Damn cheap *** thing lol I had to hold it up with duct tape.

TheHooded_Mike

Has anyone ever had a fuse that was burnt out, but you couldn't tell by looking at it?

TheHooded_Mike

The whole story here is that I first got the secondary o2 sensor code awhile back. I just replaced that today and the CEL came right back on...so, I checked the code and it turns out that the primary o2 sensor is malfunctioning too. I guess the only options are to check the resistance on the sensor or replace them, right? I'm so pissed because the secondary is a brand new NGK sensor.

EE_Chris

Yes - that's the first thing I would have done, is to measure the resistance. But you made it seem like you had both codes on simultaneously and it's a little unlikely that both would go at the same time.

TheHooded_Mike

No no, they are <U>both</U> on as of last night even after a new secondary sensor and the fuse replaced with one of the spares in the box.

dan89crxsi

I am getting the same code on my EK but I just get code 65 the heater wire (black wires) I just put a brand new o2, ebay cat (temporary fix for blown cat), and Apex Worldsport.

TheHooded_Mike

Can someone tell me exactly how to measure the resistance of the sensors with a multi-meter? I keep reading that there should be two black wires on the sensor, yet mine only has one - 4 wires and four prongs to choose from.

19slocivic97

look at your old sensor so you can pick the correct wire location, then measure with dvom, i think its suposed to be 10-20 ohms, i'm not sure though, if the heater circuit is shorted in the new o2, it may have blown the heater fuse

TheHooded_Mike

Ok I got a 13 ohm reading on the new sensor (secondary), but the old one (primary) won't give me a reading at all...what would that mean? The circuit in there is toast? I'm sending the new one back though, and hopefully the next one they send will work.

EE_Chris

It means that is has burned open, leaving it useless.

crx378

where did you read the ohms from? i have p0131 low voltage on a universal o2 bank 1, ive tried to soidering it and with out. i know i cant spell. but the code just comes right back on 2 miles downn the road

TheHooded_Mike

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EE_Chris &raquo;</TD></TR><TR><TD CLASS="quote">It means that is has burned open, leaving it useless.</TD></TR></TABLE>
Ok thanks Chris, I have a new one on the way and hopefully that'll do the trick.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by crx378 &raquo;</TD></TR><TR><TD CLASS="quote">where did you read the ohms from? i have p0131 low voltage on a universal o2 bank 1, ive tried to soidering it and with out. i know i cant spell. but the code just comes right back on 2 miles downn the road</TD></TR></TABLE>
Measure from the metal prongs for the two black wires - one of my sensors only had one black wire, so I had to figure out which was the other one (it's the wire next to the black one on the narrower side of the plug). A working O2 sensor should read 15-40 ohms according to Chris.

Both of my sensors were bad, even the new one I bought...

crx378

oh ok thanks, i too am getting another o2 sensor, my problem was that they moved the o2 sensors because of a header. i did find a place that makes o2 extension wires though, so hopefully no more cutting for me! im goind to check the ohms though just to see whats going on.

TheHooded_Mike

I have a new primary in with the old secondary now...and the CEL is gone! Now I'm gonna have an extra secondary (couldn't hurt), but why would the primary affect the secondary?? Damn screwy things rofl.