o2 sensor volts never changes
 

My o2 volts stays at 446.42 and doesn't change untill its switch off. I switch to a heated one today and it did it to. Tuner pro flags say its ready and ok. Any ideas on what may be wrong or anyway I can check it? Here's another DL,and remember the knocks is coming from the none adjustable rockers, custum length pushrods on the way.

Re: o2 sensor volts never changes
 

Have you checked the O2 input at the ECM (Pin E14), with a Digital MultiMeter, to verify that the datastream and the hardware match?

The ADS file you are using may not have the O2 defined properly.

Re: o2 sensor volts never changes
 

No I didn't know where to start, I'll have to get a digital multimeter. When I check it should it show the o2 volts mv when the engine is running?

Re: o2 sensor volts never changes
 

Yeah, it should sweep ("Switch" from high to low), while the engine is running and O2 warm.

Re: o2 sensor volts never changes
 

ok got time to try it again. It looks like when idling it jumps from low back to 446 mv untill I give it throttle then stays at 446 mv on the datalog. I got a digital multimeter and it shows around 100 mv at idle and goes up to 900-1000 mv when reving it up, is there something i'm missing? here is my bin,xdf, last data log, and aldl file if they will help any.

Re: o2 sensor volts never changes
 

and log. Its a 92 7730 ecm.

Re: o2 sensor volts never changes
 

This is what an active O2 sensor looks like. From your log the O2 sensor looks to be active and properly switching. It is just that the scaling is off. Which means that the .ADS file is probably in error. If the .ADS is OK, then the ECM is probably bad (O2 amp or ADC channel for it).

RBob.

Re: o2 sensor volts never changes
 

so where would you go from here? I don't think the 446mv on the log is real since I didn't see any on the meter.

Re: o2 sensor volts never changes
 

I would start with the .ads file. Try this: open the log you posted (11052.csv), read it into Excel, highlight the O2 volts column and create a line graph of it. Stretch the graph out wide to the right. Note that the O2 is constantly changing, just like the graph I posted.

Seems to be correct with the except of the scaling. So, either the .ads is wrong (correct it), or the ECM is bad (replace it).

RBob.

Re: o2 sensor volts never changes
 

ok first thanks for the help i'm getting. I made a stock a1,$88,and 8d bins and tried them all today using the correct masks and ads files for each. Each one showed similar on the volt changing while idling and then they all went to around 446 on acceleration. I datalogged a friends 0D mask 4.3 cpi and his 02 volts looked to be changing right ( just to make sure it wasn't me).While doing my logs I noticed on one that it showed an error in tp aldl flags. So since I have change my o2 sensor to a heated one i'm going to Auto Zone and buying a non-heated new one thats for my car (only $20.00) to see what it does.Then if no luck I guess i'll be changing ecm's. The only thing that gets me is when I used a multi-meter on e-14 wire the volts looked to jump around like they should.

Re: o2 sensor volts never changes
 

I have tried 3 o2 sensors and 2 ecm's with the same results. I checked the tps volts with a digital multimeter and it was at .81 at idle I adjusted it to .50 at ilde and goes up to 4.381 at wide open. The o2 readings seems to be alot better at idle but goes into default when giving gas. I noticed in tuner pro that the learn control always stays disabled is this correct? Could it be in my memcal?

Re: o2 sensor volts never changes
 

Just replaced my memcal out with a g1 adapter and have the same results. This thing is driving me crazy.:gocrazy:

Re: o2 sensor volts never changes
 

Rbob,

Per that pic if my WB reads OK... and the O2 is reading around 900 all the time at idle then when she gets some gas it goes down to around 800 or so whats happening?

Sorry no log...

Re: o2 sensor volts never changes
 

In order for the NB O2 to oscillate as shown in the picture the ECM needs to be in closed loop. Just sitting above 700 mV or so shows that the exhaust gases are rich.

RBob.

Re: o2 sensor volts never changes
 

Early on when I started tuning, I had the same problem. My O2 reading did not change, I couldn't figure out why until I started to research the problem.

I learned that the TBI ECU I was working with substituted that value as long as the O2 reading did not rise above a certain amount, I think 100mV. The engine had a miss that was allowing a huge amount of oxygen to the sensor making it read lean.

It could just be that for some reason the sensor is getting too much air and reading lean.