89 Code 13
Thread Starter
Drifting
Joined: May 2011
Posts: 1,532
Likes: 53
89 Code 13
Hello friends,
Check engine light came on twice today. I pulled codes and got a code 13 (oxygen sensor). Only change in conditions is that I took it to a touch-less car wash and put 10 gallons of regular gas by accident, first time for both. Never car wash & always super. One out of laziness and the second by accident. Should I wait until I get a full tank of super or what should i check for before replacing the sensor.
1989 with 114k no mods.
Thank you
Check engine light came on twice today. I pulled codes and got a code 13 (oxygen sensor). Only change in conditions is that I took it to a touch-less car wash and put 10 gallons of regular gas by accident, first time for both. Never car wash & always super. One out of laziness and the second by accident. Should I wait until I get a full tank of super or what should i check for before replacing the sensor.
1989 with 114k no mods.
Thank you
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
Error Code 13 is interesting...
I looked at the firmware for my '86 (BUA -- same ECM as an '89) and found you get Error Code 13 if:
1 - Engine run time is greater than 120 seconds.
2 - Coolant temperature is greater than 157 degrees F.
It waits for the above two conditions to be met before doing the test. You get the error if:
3 - O2 sensor voltage is between 343 mVDC and 538 mVDC for more than 3 seconds.
Based on the way the firmware operates and the characteristic curve for an O2 sensor, I don't see how it could meet condition (3) unless the O2 sensor is bad.
Normally the O2 sensor output varies back and forth between about 200 mV and 800 mV. It takes 1 to 2 seconds to do this, so staying between the parameters in (3) for more than 3 seconds means something is wrong.
I looked at the firmware for my '86 (BUA -- same ECM as an '89) and found you get Error Code 13 if:
1 - Engine run time is greater than 120 seconds.
2 - Coolant temperature is greater than 157 degrees F.
It waits for the above two conditions to be met before doing the test. You get the error if:
3 - O2 sensor voltage is between 343 mVDC and 538 mVDC for more than 3 seconds.
Based on the way the firmware operates and the characteristic curve for an O2 sensor, I don't see how it could meet condition (3) unless the O2 sensor is bad.
Normally the O2 sensor output varies back and forth between about 200 mV and 800 mV. It takes 1 to 2 seconds to do this, so staying between the parameters in (3) for more than 3 seconds means something is wrong.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
13 pretty much means no signal at all so make sure the wire hasn't melted or the Connector hasn't fallen apart. If not check voltage from the Sensor with the engine nice and toasty and if nothing there, replace it. If there is a variable voltage then the wire is open before the ECM or the ECM is bad.
I'd fix the 13 before tackling the 44 which can be caused by several problems including water or coolant in the combustion chamber or a broken header check valve or a vacuum leak of some sort or it may just be a bad Sensor - so fix that first.
I'd fix the 13 before tackling the 44 which can be caused by several problems including water or coolant in the combustion chamber or a broken header check valve or a vacuum leak of some sort or it may just be a bad Sensor - so fix that first.
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Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
I just had a similar problem myself. I saw 13.9 MPG on my display, which is way low. I mostly drive in town so my MPG is usually in the 15 - 16 area. I checked codes and got a 44. I hooked up Diacom and saw 0 volts from the O2 sensor. Hmmm... seems a little low ;-). I just replaced it about a month ago with the "good guy" AC Delco AFS22 (which had a Bosch part number on it). Back to the old AutoZone Bosch and things are definitely better.
I replaced it last night and I was checking it today and saw some really weird stuff going on. When I first started driving, the O2 sensor was showing around 30mV, which it should do when it's cold, but Diacom was showing Closed Loop mode, which makes no sense (O2 sensor voltage is way too low to go into Closed Loop). Also I was seeing BLM of 160 (maxed out rich), which sorta goes with the low O2. The weird thing was the Integrator was bouncing around 128 - 140 but the BLM wasn't coming down. I guess Diacom was lying to me about being in Closed Loop. The BLMs finally started coming down as I was getting close to home, so I still don't know for sure that everything is OK. More driving needed...
I replaced it last night and I was checking it today and saw some really weird stuff going on. When I first started driving, the O2 sensor was showing around 30mV, which it should do when it's cold, but Diacom was showing Closed Loop mode, which makes no sense (O2 sensor voltage is way too low to go into Closed Loop). Also I was seeing BLM of 160 (maxed out rich), which sorta goes with the low O2. The weird thing was the Integrator was bouncing around 128 - 140 but the BLM wasn't coming down. I guess Diacom was lying to me about being in Closed Loop. The BLMs finally started coming down as I was getting close to home, so I still don't know for sure that everything is OK. More driving needed...
Last edited by Cliff Harris; May 27, 2012 at 01:49 AM.
Thread Starter
Drifting
Joined: May 2011
Posts: 1,532
Likes: 53
Cliff, I bought the Bosch only bc I couldn't wait until next week to get the Densi brand delivered. But according to many post here the Bosch are problematic . I'm off to fight the o2 again today. I'll get that thing out 1 by hook or by crook
Thread Starter
Drifting
Joined: May 2011
Posts: 1,532
Likes: 53
Won the day. Replaced the o2 sensor PB blaster heat more PB blaster and then finally came out. Test drove it for 15 miles no codes. I washed, waxed even coated the weather strips with silicone. Ime for me to wash and go out fona drive. Thank you all For the help.
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
The Bosch unit I put in came in an AC Delco box. It said AFS22 (Air Fuel Sensor). The AutoZone unit had a different Bosch number. I'm really curious to know what the differences are between the various Bosch units. I wonder if Bosch has that info online somewhere.
I have the original AFS16P AC Delco unit that came in my car from the factory. It looks way different from the Bosch unit and has "AC SPARK PLUG MADE IN USA" stamped on it. My photographic muse has inspired me:
I have the original AFS16P AC Delco unit that came in my car from the factory. It looks way different from the Bosch unit and has "AC SPARK PLUG MADE IN USA" stamped on it. My photographic muse has inspired me:
Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 412
From: WV
...WW
Slingshot
Joined: Dec 2001
Posts: 3,817
Likes: 24
From: Charlotte NC
with WW. I change mind out every 3-4 years no matter what. Have not had an O2 sensor problem in decades. FWIW