AFR randomly went to 21.8 under high boost
 

97 Miata MKturbo, FF640 injectors, MS3pnppro. I have 700 miles on my rebuilt 1.8. 84mm 8.8:1 pistons, manley rods, wiseco rings, BE pump, etc.

I have kept the boost low while I have been getting some miles on the engine, but now I am turning it up. Its been fine other than I cant seem to get the turbo to produce much over 13psi. My AFRs have been fine until this morning I took it out and did several WOT pulls while datalogging and all was good until I floored it in 3rd gear around 3k rpm trying to see what my boost is and I noticed my AFR gauge reading 22, so I immediately backed off. It then drove home fine, but checking the log and yep I was at 21.8 AFR while at 12psi and WOT. I have no idea why though. I drove it a little more keeping a close eye and it the AFRs were back perfect even under boost.

I attached the log and my tune (the high AFR is at record 8332). I have a race next week and that just freaked me out. I don't want to ruin my new engine. Any thoughts?

Likely a fault condition for you O2 sensor controller. Many display an un-realistic value when they don't know the value, or have other electronic issues.

Post the details of your O2 sensor.

EDIT: read the instructions that came with the sensor / controller / gauge for information on this.

I am running the Innovate mtxl that I Installed with the ms3 last year when I first installed the turbo. Hopefully it was just an error and I really wasn't running that lean at 12psi lol. Scared the crap outta me.

Stupid ass MS3 and it's EGO correction doing shit that's literally fucking impossible. Within less than a second it goes from zero to -10% to +10% and the right back around to 0%. It does the same exact retard shit when you finally let off the throttle.

Makes sense. Great code, MS3 is the BEST! User request, supposed to do that. Does the dome control work? Not doing anything till we get test results from that!

people use ego correction in boost?

Yeah, I did in low boost before EGO was changed and made completely fucking retarded. I run e85 and non aggressive spark, street car. With how it works now you just might be running EGO in boost without knowing it. It will stick and lock at non zero'd values, especially if you are in an active EGO area and roll into one with no authority or corrections allowed.

Instead of swinging wild like his does mine will spike to full lean correction when I let off. Then it coasts into overrun and turns EGO off. It will stay at 90% EGO till I get it back into a range that allows EGO correction.

Some retard over on megasquirt forums actually wanted that. JSM added it in and left no way to turn it off. Fucking brilliant.

Could it have been a misfire? That usually reads super lean.

Just an update on this. My innovate MTXL wideband is getting stuck reading full lean sometimes. I dont know if it is the actual o2 sensor part or the gauge causing it. I am going to recalibrate the sensor and see if that helps. Has anyone else had issues with the MTXL wideband? Mine reallly isnt very old. I have only had it on the car for 1 year and only like 3000 miles.

MTX-L Plus burned new sensor in 200miles... edit: Showed full lean then E9 iirc.

Bought a replacement sensor and put a power switch on the controller to turn it on after 30 seconds of running.
Some people say, that the heater is very aggressive on the Innovate controllers and that heating up before the engine is started, can weaken the sensor very quickly, because condensed water can "shock" the sensor and shorten it's lifetime.
Building a heat sink is also suggested by Innovate, can be as simple as this:
https://cimg1.ibsrv.net/gimg/www.mia...d7c518f5c1.jpg

Ive heard some stories about the Innovate stuff running the heaters full tilt all the time, but Im not sure if thats true.

I think as long as you start the car as soon as you turn the ignition on, youre good. But if you let it sit there and heat up, youre asking for trouble, especially when the engine is cold and its going to be blowing loads of cold condensation and fuel through the exhaust initially.
Ideally you could set the ECU to turn on the WB controller once the engine is running (could just base it on RPM).

Wideband sensors require a very specific temp to read properly. I think it's 780c +- 20c. If the heater was run all the time you'd be way over temp. I believe the heating element is controlled through PWM with a PID strategy.

It does seem like innovate controllers kill sensors at a higher rate than other controllers. Maybe they just run the heater at a higher duty cycle for initial warm up.

Either way you ideally want the engine running before the sensor starts warning up.

I wish I could help, only wanted to add back in 2012 I had a similar issue with an Innovate LC-1. I would randomly get stuck reading lean, no error codes, just stuck. I never figured out what got it to reset but I remember plugging it into my laptop and going through the setup process over and over to verify everything was good. They finally agreed to check it after I mailed it back and they blamed my wiring. Only, my engineer brother that built fuse panels for GM and wire harnesses for a company that supplied Polaris and others, he checked and verified my wiring was fine. I ended up giving up on the Reverant MS2 Enhanced and LC-1 selling them at a slight loss to another Miata owner that raced his car. He never got back to me about the WBO2 sensor/gauge but I read other issues that weren't adjustable like the Check Engine light flashing for water temps that weren't all that high.

Although I'm making some progress manually tuning fuel on the Hydra Nemesis 2.6 that was in the new to me '04 MSM (FM2 Garret upgraded), I'm getting close to ordering an MS3. I don't think I'll be installing another Innovate WBO2 product.