It's a code 13 Please help me please help me !

[langleylad]

This is getting to be a real pain in the a## ! . I've had this problem for way to long now . The " check engine light " has been long for so long now , I'm suprised it hasn't burned out . It's my 88 S10 4.3 auto . Code 13 is an open o2 sensor circuit . I have replaced the o2 sensor numorous times . Replaced the ecm , checked the voltage at the sensor as per instructions in both the Chiltons and Haynes manuals , voltage checks out perfect . The check engine light is out until the engine reachs operating temp. about 180 - 190 then it comes on . If I stop for gas , coffee , what ever and restart the engine the light stays out for about 5 mins. then goes back on . Sometimes while driving it will go out . I have to take it through emissions testing in about 3 weeks and it will fail if the light is on which will mean I can't insure it . I hate the idea of taking it to our local GM dealer at over $100 an hour . It's been driving me F'N crazy . If you can cure this for me I'll send you a 6 pack or something ! .

[Mater]

have you checked the voltage with the engine at operating temp? maybe the wire has a brake that only opens up when the enigne gets hot but when it's cold it still makes a connection

[Schtauffer]

Take the bulb out.

[TC]

Take the bulb out.

That's doesn't erase the code that is stored in the Computer and that is what is going to fail him when he goes through emissions.......

[chevy3100truck]

they don't check OBDI cars/trucks for codes here

[Beagle]

They don't pull ALDL data on an 88 here, only sniff and dyno. If it's running clean, they'll pass it... pulling the bulb isn't out of the question. Denton county is part of the EPA Dallas Fort Worth disaster zone... our testing is about as bad as Cali's. I'd be more worried about what it was doing to fuel and timing.


The 13 is dead 02, could be it's off it's scale? Is the exhaust pipe black, was the old 02 sensor blackened up? Here's the beauty of the Emissions test - when they put it on the rollers (if y'all do that) and sniff it, and it's likely they'll be able to tell you which way it is. Narrow band O2's don't have much range, so if it's off the chart one way or another the ECM will throw a code.

[langleylad]

The truck is always running in Open Loop mode which means running rich as the tailpipe shows and as gas mileage shows .

[Beagle]

I saw a lot of "leaky injector" comments ... wonder how much a junkyard throttle body runs? It might be worth a try if it's like 20.00 or something.

[langleylad]

When a code 13 shows the ecm puts it into open loop mode which means running rich . There has to be something I'm missing here . New o2 sensor , new ecm , correct voltage at the sensor ( unpluged , key on , engine off ) . It's a one wire sensor , so I imagine the sensor is self grounding .

[Teddyzee]

Have you checked the continuity of the circuit, from sensor to ECU?

[Stich496]

light comes on, when warm only because the ecu doesn't use the none heated o2 untill then..
loosen the bolts/nuts at the front pipe and wiggle the pipe around, getting the rust off the ex. manafold and the pipe connection, the sensor mostlikely lost it's grounding through the exhaust.. run a junper to test

[langleylad]

THIS IS DRIVING ME CRAZY !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! I have grounded the sensor , not the problem . I wake up in the middle of the night and think about what the solution could be . I 'm running out of ideas . Come on guys a prize for the solution , you boys know your stuff ! .

[82z]

are you using a scanner or reader? a scanner will show all of the parameters . When i worked at the garage we had a car come in and the colant temp sensor failed so it read -42' . I wonder if a failed colant sensor is flooding out your o2 sensor.

[Bamfster]

It's hard to troubleshoot things over the 'net, but I would tend to agree that it is something else (other sensor, ground, etc) causing the code your seeing. All of the sensors and systems work together, that's why a scanner is a better tool than a reader. Lately I've been seeing a lot of codes show up that have nothing to do with the actual system the code points to ....

[langleylad]

Thanks guys , good points . I was wondering if the temp sensor could be part of the problem . I'll check it out and report back . Thanks again .