Brand new Innovate MTX-L sensor bad?
 

I recently bought an Innovate MTX-L Wideband from DIYAT for my '99. Today I wired everything up and despite our attempts we cannot get the wideband to read anything other than 22.4. We wired the sensor in by splicing into the power windows for a switched 12v source and wired the ground to a 12mm bolt on the head (Back right near valve cover). We then calibrated the sensor with it out of the exhaust as per the instructions. However, nothing will move it off of 22.4:1. I would blip the throttle, nothing. I turned off the car, still 22.4. So we pulled it out and re-calibrated it and still nothing but 22.4:1. Any suggestions? We plan on testing it in the morning with brake cleaner but I wanted to make sure to cover all of my bases. Maybe a bad sensor? Would DIYAT replace it or cover it by warranty? I thought I read somewhere that only the controller/gauge was covered by warranty. (Edit: I have emailed them, waiting on response)

Ok so this morning we tested it using the brake cleaner method. It read full rich for the first time. Now the question is why aren’t we getting an accurate reading with it in the exhaust.

We put it back in the car and it appeared to be reading correctly however after a minute or so it went back up to the max value. Maybe exhaust leak?

So in theory if it’s an exhaust leak it would get “better” as airflow increases past idle levels, but when I blip the throttle to get more gasses flowing nothing changes. So I’m starting to not think it’s an exhaust leak. When we tested it, it worked at idle until the car got up to temp so could it be something correlated to that?

I ordered another sensor so I can get my car running while emailing innovate in an attempt to get another. I don't see how it could be anything other than the sensor's fault at this point. Edit: Also, I moved the car and while doing that O2 sensor read off the charts. I am thinking that if it were an exhaust leak it really should've read something while it was "driving".

Most likely an exhaust leak. Can you post pictures of it's location and the rest of the exhaust?

it’s in the stock front 02 sensor position with the stock exhaust manifold. Do you really think an exhaust leak could skew my readings by that much? I couldn’t get it to come off of 22.4 with throttle. I can post pictures tomorrow if the new sensor doesn’t automatically fix it. If it’s not the sensor well I guess I have an spare now.

I ended up buying a gasket for the 3 bolt flange right after the collector. We recently did my clutch and after reading some numbers online I think we didn't replace the gasket. I guess I have an extra sensor now too lol

From Hotrod.com (High duration cam LS or something):

That's a handy test

I replaced the gasket shown in the picture. It didn’t make much of a difference if any at all. Still 22.4 at idle but now it will react if I blip the throttle.
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Oh and while it was up off of the ground I listened for exhaust leaks and couldn’t hear anything at least before the cat. I didn’t really bother with the rest because it was so far downstream.

Sprayed the exhaust flange with soap water after a cold start to look for leaks. I didn’t see anything. I also removed the heat shielding to look for a blown out manifold gasket. Didn’t see anything like discoloration from exhaust blowing by.

Any chance you damaged it while installing it? Can you take the sensor out and take a pic?

Back in 2012 I bought an Innovate LC-1 WBO2 sensor and wired it exactly as recommended to a plug and play MS2 enhanced. Same thing as you're experiencing, it'd run for a short time before getting stuck reading full lean. My engineer brother that designs and builds wire harnesses and fuse boxes checked my wiring and agreed it wasn't the problem.

I contacted Innovate and mailed it back but they returned it saying nothing was wrong. I reinstalled it and had the same problem. When it would freeze reading lean I had to go through the setup process over and over until it would eventually allow my laptop to connect but after a short period of time it would again freeze. I gave up as I was also having trouble tuning idle and sold it all. Good luck dealing with Innovate, they were useless and couldn't replicate the problem so they returned it refusing to exchange.

I'm again learning to tune but this time it's on a 2004 MSM that got the full Flyin' Miata treatment way back in 2009. Unfortunately it's still running Hydra Nemesis 2.6 but I'm thinking about upgrading to 2.7 for a decent price versus paying to unlock fuel auto tuning capability on this crappy 2.6 software.

Another update: I checked the spark plugs to see if they were fouled because I know a misfire will read as lean. I had two cylinders that were fouled (1&3) but my question is: would two misfiring cylinders be enough for this lean of a reading? I’m typing this as I ride to the parts store to pick up new ones.

Edit: Update nope not it

We took extra care not to do so because of a friend’s horror stories with his sensor. There were a couple small dings on here and there while putting it in but it was never dropped or hit hard. My new sensor will be here Tuesday if that’s the case.
https://cimg9.ibsrv.net/gimg/www.mia...466d189af.jpeg
https://cimg1.ibsrv.net/gimg/www.mia...ee03eb2c2.jpeg
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I think at this point I’m just waiting it out until Tuesday. If the new sensor doesn’t fix it I’m going to pull the trigger to buy a set of headers. It was something I’ve been wanting to do anyways. I’m just at a loss for words. I have tried everything I can think of.

I hooked up the new sensor and same exact thing. I even re-did the ground and soldered it instead of the crimp connectors.

I need some input. What else is there to try? We put in new exhaust gaskets. We recalibrated both sensors countless times. We completely replaced the sensor with another brand new Bosch sensor. I made sure the ground is good and soldered. I ordered a EGR block off kit from racing beat. Before I installed my MegaSquirt I was getting an error code to the extent of that excessive flow from the EGR system. Is it possible that this is responsible for my bad o2 readings? its something I had already planned on doing and it can’t really hurt me so I figured why not go ahead and do it. Could a massive exhaust leak be caused by this? I think I might have a vacuum leak and haven’t been able to find one. Could this be responsible for both?

If I were to need to drive the car to an exhaust shop or somewhere like that to get them to inspect it, could the stock ECU function safely enough to not blow up my car? This would be like driving it without a front O2 sensor. But honestly if my car is doing this with the Wideband it probably was causing a lean condition with the stock sensor too. That makes me ask the question is 22-23 mpg normal with a stock ecu on a ‘99? Was the sensor reading lean and messing up my MPGs? Just thinking out loud here hoping for a little help.