code 13


Beer Snob
Staff member
May 24, 2001
How bad does the code 13 affect performance? I would figure a bad O2 would kill performance. What do you think?
It can hurt your peformance pretty good. I know when my 02's failed it would cause the car to lean out too much. It can effect spool up also. You really should get a good one soon as possilbe.
The reason I ask is because I went to the track last night and the car went 116.7 mph with with a code 13 stored in the computer.I'm wondering how much performance I lost. I did reset the ecm between runs but before I made a pass the check engine light came on, but after the burnout it would go off. I brought an extra sensor with me but I couldn't change it because of the tools I lacked. I guess sooner or later I'll learn. Thanks for the reply. Anyone else?
Hard to say how much performance lost if any it could be causing the car to lean out a little right now and actually cause the car to run faster but be careful running a faulty 02 as it may lean you out a little to much. Then there are some 02 that fail and cause the car to run rich which really would probally hurt you performance more. As far as lean goes you dont want to pop and blow a head gasket.

I was wondering why on the way home the check engine light was on (the whole way). I figured the O2 sensor was done. Well I noticed when I went to change it a little while ago the connector was unplugged! When I was at the track I forgot to plug it back up after trying to change it. So my last pass was 11.62 @116 with the O2 sensor disconnected. Did this hurt the performance? I would think. But what the hell do I know I can't even plug a sensor back in. Damn I'm a JACKASS.
Ouch! So you ran the 1/4mi in open loop mode? You're lucky that didn't blow up!
Anyone?? I spoke to John at Quad Air today and he said the car goes into "limp mode" when a code is set. He said it should have hurt the performance badly. Any input?
I think the car does go into limp mode if it sees no O2 reading, BUT, I also think think the Computer ignores the O2 at WOT anyway.....
Warpspeed, I have heard that before. I am trying to figure out this problem. My car went it's fastest with a PT51 with 009's and a front mount intercooler as compared to a 45a V4 and 55's with a 206/206 cam. WTF? I don't think the front mount makes that much of a difference compared to a V4. The cam should have helped it, the 55's should provide the fuel.
The time the car went it's best was on a 40* day with a proper cooldown. I think the coolent temps after the burnout was 140*. Last night the coolent tems were 170* after the burnout. My car seems to love being run cold. I have noticed as much as 5 mph decrease by not letting the car cool between runs. I know one thing, it's not running like it should. My combo shoould be running somewhere in the mid 120's. I wish I would have never gone this far. I should have stayed with the smaller turbo. Thanks for listening to my whining.
there is no input to the ecm from the 02 at WOT, so will not affect performance, per se....however, at less than WOT, you could have some funny things during spool will get bad gas mileage, etc...but really no effect when at WOT
Chris and Woody, thanks for the replies! If I had to guess I would think the converter may be the culprit. It's a multi disk Vigilante and I am locking it up as soon as I pull to the line. I think it may be too loose. It's a 7 pump. I told Red about it and he said I was the first person he's heard of that was using one. I think it stalls around 3800 rpm. It may not be efficient for the combo. I have a friend with an LS1 that had the converter restalled for higher rpm and lost about 8 mph. He changed converters and the car went from 108 mph to 116mph. It stalled exactly what he wanted, but was slipping all the way down the track. I wouldn't think a lock up converter would slip but his did. What do you guys think?
A lockup converter will slip if you don't lock it. A precision will slip big time if you don't lock it. Otherwise its supposed to not slip.

If you are locking the converter, I don't think thats the problem, yet. It only takes a little extra fuel to decrease performance dramatically. The O2 sensor was MIA, but were you using something else to tune with? What about knock?
Chris, no knock on C16. Maybe .5 in a couple of frames but that's the most the scanmaster recorded. I am also not ruling out the valve springs. They are the ones Poston's sells. Maybe they are not strong enough for the comp cam. The have about 13K on them as of now. If the converter isn't slipping then it has to be someting else. The car should have gone over 120mph easily. Did you try out those chips yet? Thanks again.