torqueaddict

If the O2 sensor/wiring is ok, what would a code 13 indicate as far as my tune is concerned?

I've been getting a code 13 (occasional engine light - all the time during data logging). Most of the time I'm at 444mv (I think it's mv) It barely changes at all except I did see it as low as 260 and up to 900 - maybe during full throttle.

I swapped out the AC heated sensor for the original Denso- same readings. Tested voltage at sensor under car at idle- steady 800 mv.

Anyway, if the sensor and wiring are ok, what would that indicate in the tune? I am on the lean side (long term=150-160, short=140-150)

I have an 89 TPI 350, Vortec Heads (SD intake), Edelbrock Headers.

thanks in advance....

Theking

iTrader: (1)

youre lean if you logging with tts datamaster (it should be the same in any program..)
128 is stoich and everything above 128 is lean and everything under 128 is rich.. You have to make it as close as possible to 128 when cruising / idle, when giving alot of throttle you should be rich.. not to much but rich..

Where does the o2 sensor sitting on the headers, in the worst case you have to move it or buy and preheated o2 sensor. with a heated it would start jumping around thoose values in ~5 mins..

had the same thing on my, it didnt start, I bought a new one, and that didnt work, got it replaced again and then it works (so the first 1 was busted from factory).

torqueaddict

Thanks - I did crank up the fuel pressure and it seemed to help (more O2 fluctuation and closer to 128)

But the mv seemed to settle down near 444 and not change much if I'm not on it, but when I am at WOT it's changing rapidly then over a few minutes it settles down again. Also somtimes it goes in and out of open loop.

Does this sound normal? Also I am running a heated sensor now.

Theking

iTrader: (1)

in WOT the ecm will ignore the o2 sensor and run from pre set tables in the prom. So how it moves in WOT dosent really matter..

it shall be moving from 200 to 800 constantly when hot. or else its broken or something else is wrong, it shall never be still when its hot and ready.

How long to you run your engine, and is it on idle or while driving ?

torqueaddict

I was running for about an hour so that shouldn't be an issue. I doesn't constantly change, but it does change a lot during aggressive driving then it settles down to 444 mv.

I tried to check if the wire is fried on the exhaust- causing an intermittent open circuit - it was hard to tell.

Maybe I should disconnect the sensor and read the voltage with a good meter to check the sensor.

thanks for the advice.

Theking

iTrader: (1)

Yeah unplug the sensor and see if you get any SES light and codes, and then measure with an good meter. it shall move around from 200 to 800 constantly when hot and ready.

get back here with some info later, take care

torqueaddict

datalogged while parked last night - it stayed at 444mv / open loop for a while then went into closed loop and started changing nicely - about 1 cross count / sec. Seems fine now - even wiggled the O2 wires while running and still have great cross-counts.

thanks - whatever it was seems fine now.

afremont

If the sensor is not getting hot enough, it can act as you described.

torqueaddict

Any advice on how to test an O2 sensor? Is there a way to ground the signal wire and check the datalogging values, etc... to rule out ECU / wiring?

Still having some trouble with this - While the car is warming up the O2 is a 444, no xcounts. It warms up, goes into closed loop, and o2 is all over the place, xcounts are great- car runs great and I can do some tuning.

After about 15 minutes, I go into open loop, O2 at 444, no xcounts.

I have a new AC delco heated sensor , (good voltage at sensor) and I tested the signal wire and I get a steady value. I was wondering if a meter can detect the rapid change in the sensor.

I think 444 = no signal. Is there a way to ground the signal wire to make the computer react to verify the O2 is bad? I don't want to throw more parts at the problem.

torqueaddict

FYI: It's been a while but I finally got it -
I cut the tan wire and attached it to the body and instantly saw the O2 swinging - thanks for the help

IrS89IROC

I just had the same problem. i had to splice the ground wire for the o2 sensor coming out of the ecm and run a new ground and now it works great.