93 5.7 cat delete o2 sensor light

[ol-Betsy]

You have a 1993 model with a heated o2 sensor? Or did you modify the truck from a non-heated (one wire) sensor?

If modified, how was it wired in?

But most importantly.. we're 3 pages in and I haven't seen what specific code it's setting mentioned, or did I overlook it?

Richard

It has a 3 wire o2 from the factory as far as I know. Nothing was changed on my end but I've only had the truck for about a year. It was all stock low mileage. It threw the code for 13 which for this truck (keep me honest) relates to the o2 sensor

 

[scott2093]

I'll trace the harness back

Have you done this yet?
My 93 comes with a one wire. Maybe there is something goofy with wiring if someone previously upgraded the sensor.

 

[someotherguy]

Have you done this yet?
My 93 comes with a one wire. Maybe there is something goofy with wiring if someone previously upgraded the sensor.

I haven't seen a '93 with a factory heated o2 but that doesn't mean they don't exist. Wiring diagrams in the '93 factory service manual would tell the story.. and also comparing connection points and wire colors may help determine if it's a factory install or retrofit.

Code 13 is o2 sensor circuit open. That would be on the signal wire for the o2; I'd suspect a break somewhere or possibly a defective sensor.

Richard

 

[ol-Betsy]

I haven't seen a '93 with a factory heated o2 but that doesn't mean they don't exist. Wiring diagrams in the '93 factory service manual would tell the story.. and also comparing connection points and wire colors may help determine if it's a factory install or retrofit.

Code 13 is o2 sensor circuit open. That would be on the signal wire for the o2; I'd suspect a break somewhere or possibly a defective sensor.

Richard

Like I said, I just replaced the sensor. People keep saying that the sensor is bad. It's not lol. There definitely isn't any jimmy rigging to the wire harness. 3 wires come out with the 3 wire connector. I'm not even sure how a single wire sensor would connect. They had 2 totally different connectors. The entire harness still has the factory wrapping around it. Haven't yet found where they lead to under the hood but I see the harness goes up the drivers side of the fire wall. I never get away with an easy fix lol.

 

[someotherguy]

I hear you. I proposed more than one possible cause, so let's not ignore all of them..

Richard

 

[scott2093]

Like I said, I just replaced the sensor

In the beginning was a bit confusing tbh

If you have a 1 wire sensor, it may not be getting hot enough to work, due to less back flow restriction. A heated 3 wire will work better.

I did get the 3 wire heated sensor for that exact reason.

People keep saying that the sensor is bad. It's not lol

Again, a little confusing. You said you didn't have a scanner and haven't updated your progress on wether or not you took readings of the sensor via a scanner or were able to get your tuner software figured out.

Many are saying that the exhaust (newly installed?) probably doesn't have anything to do with it..even this....

Mine rotted off and never set a code even with the open Y pipe. Also heated and a 4.3 truck!

New doesn't always mean good.....I had a thread about my struggles with 2 brand new AC Delco/GM knock sensors....had to go NOS....
. and, as mentioned a code 13 is pretty clear in the manual on what the causes are likely to be.
But idk... Will be interesting to hear the solution
Stay with it....you'll get it...
maybe a multimeter reading of the sensor outputs?

 

[scott2093]

I haven't seen a '93 with a factory heated o2 but that doesn't mean they don't exist. Wiring diagrams in the '93 factory service manual would tell the story

I see...Says heated o2 in LB4 only in my wiring manual..
There's also a mention of an o2 sensor back by transmission

 

[ol-Betsy]

I haven't figured out the tuning software. That's a little out of my league and fetching what I need has been a struggle. No shops or parts stores around me have an OBD1 scanner that gives live readings. I've been told on this thread and in person that it's probably a faulty sensor. So I replaced it. Same story.

I'm curious with how the exhaust could possibly throw the code. Lower exhaust temps from going from cast manifolds to a more flowing stainless? I have the sensor in the y-pipe collector because that was the stock location. I'm just now noticing that the bung is located just before the driver's side fully gets into the collector. The catless cat pipe I have also has a bung. Ive moved the sensor there hoping that could help with it reading 100% of the exhaust flow. The drivers side header also has a bung there. Would it be worth trying that point to get a hotter reading?

I don't know what else it could be. So far I've only been informed on the sensor itself, the harness, and now the exhaust. The sensor alters the fuel trim, but what if the trim is off from something else. Would the sensor then throw a code if it was running rich/lean? Sounds backwards to me.

 

[scott2093]

Have you downloaded the emissions and driveability manual for your truck? It'll have a bunch of useful info, including where the o2 sensor is intended to be from factory depending on your model. Apparently it varies quite a bit which is surprising to me. Pay attention to the series,engine code/rpo..etc..

88-98 Service Manuals

Over the years I have collected a bunch of GM service literature. Links to PDF Scans of service and STG manuals and a links to the Parts manuals. You'll need the FREE Adobe Acrobat reader to open these files. Get it directly from Adobe here {http://get.adobe.com/reader/} If you're not...

www.gmt400.com

 

[ol-Betsy]

Changing the location did nothing.