UEGO nightmare
 

It has been 2 weeks and I still cannot get my WB working correctly. 1.6, MSpnp2, AEM UEGO. I have ran power from the fusebox, and the battery. I have read numerous accounts of people with conflicting stories on grounds, so I'm asking you all.. I have ran grounds from the radio area, the trunk battery ground, the battery it's self, and to the engine and engine bay, I have NOT ran it to the ECU sensor ground, yet.. Wanting experienced opinions, I keep getting erratic readings and full lean readings, it isn't the tune, The sensor tested good (gas/rag) test.. Any help appreciated, this is becoming a mini-hell.

Might be a dumb question, but you have calibrated it in TS, correct?

Are you getting these readings from the gauge, in tunerstudio, or both?

log of erratic readings?

I'm getting it in TS, and on the afr.. But the car seems to run fine through all of this. I will get a log later today and post it if I have time, and yes it is calibrated in TS

Sounds like you just have a bad gauge. Good grounds, bad gorunds... there is always an offset you'll have to account for, but it will be consistent, not erratic as you describe.

The plot thickens. I had the gauge working correctly, after fighting with it just as I'm doing now.. The alternator went bad, so I replaced it and the battery (it was needed too) and wired the ground to the battery just as it was before replacing, and I'm back to square one with it, erratic readings.

Now grounded to ECU sensor ground, power from fusebox.
At idle: will idle at 12-13 afr for an unpredictable amount of time; and them go to 18.3 and stay
Under load: unpredictable, sometimes gets dead on readings, others it's just full lean.

O2 bung in exhaust is solid too? No chance of it wiggling around or reading extra oxygen i.e. exhaust leak?

Just crossing things off at this point ha.

Yessir, I've been there too, I did find a leak about 4 inches after the o2 bung, and thought "woohoo", fixed it, caught the happies thinking it was finished, it was 12:40am, and 37° outside.. Started the car, and it read correctly (14.1-14.7) for about 90 seconds and then BAM, afr's bouncing from the 12's to full leans at idle.

Hmmm, it has to be a bad gauge then.
Or bad connections going into the back of the gauge, maybe there is play there and it causes it to read strange.
Other than that, I'm out of ideas.

I totally appreciate the input though, I'm considering just replacing all of it instead of just the gauge, it's so frustrating!!

haha no problem, I tried. I think I saw a aem wideband on the sale thread. Might want to check it out

Here's a question for others using megasquirt.. In fuel settings, I think it's under "injection type" or something of that nature, it is set to "4g63".. Anyone else running MS on a 1.6 NA, and have a different setting on this?

That would be the ignition trigger type, not injection. And yes that is correct for a 1.6 using a CAS.

Well, I think I've figured out my problem.. I tested the sensor AGAIN.. This time it tested bad, in the towel it stayed and full rich for about 8 seconds and then shot to lean.. Tested 4 times with the same result. 4100 gauge with 4.2 sensor, and I can't seem to find one that is an exact match, I've found some that you have to cut the connector off and splice the old one on to.. Nah, so I ordered a whole new UEGO a few minutes ago, I bought the one I have now secondhand, I will let everyone know the results when it comes in. I appreciate all for the help, I'm just unsure why it tested fine the first time. Oh well.

Because it is intermittent. That's how intermittent things work, intermittently.

Intermittent working part. Constant problem.. Oh well.. New WB is supposed to arrive at my shop at some point today, hopefully I'll be able to install tonight, if I can get outta here at a decent hour, sucks though because, no room in the garage, old TR6 in the way, POS.. All dependent on weather because in cold weather, I am nothing more than a little old man. 😂

New wideband went in last night, works exactly how it should, but with me tuning on the bad sensor, my tune is garbage, but the WB is actually telling me that now, I appreciate all of the input and opinions on this, very helpful. Thanks guys!

Glad to hear you got it set straight. The world is yours now.