Crazy AFR, not sure what to do. HELP?
 

Hello all, I have been chasing a series of gremlins that pops up one after the other. The first gremlin was fuel pump not running. It turns out to be a blown fuse which I fixed/replaces.

I now have a new gremlin. My AFR is all out of wacked! At idle per my Innovative MTX-L gauge, it reads from 14-17. I'm okay with my AFR in the 14's but not in the 16 and 17! I thought my Innovative was reading bad so I unscrewed it form the exhaust and calibrated it. This was a fail as the AFR still reads 14-17 in idle. I asked JWick what he thought. He said maybe it's a bad O2 sensor. I ran out and got a new one and replaced it. I calibrated it before I screwed it into the exhaust. Agian, I'm still reading 14-17 AFR.

I'm at a lost of what it could be that is causing my crazy AFR.

Per Uprev if I'm reading it correctly, my AFR is spot on good.
http://i226.photobucket.com/albums/d...pssebyuisa.jpg

The car runs fine otherwise. I can still get her into boost no problem (only hit 3lbs), starts up fine, everything seems fine fro what I can tell. I was getting paranoid and thought I heard a tic but it might just be me. I also did an oil change and looked at all my clamps to make sure they are all on good and tight. Everything checks out.

My one buddy suggested checking my spark plugs. I installed the turbo kit around 39,xxx and now have 55,xxx.

Any suggestions? My car has been sitting in the garage for 2 weeks now. I want her running well again. My local speed shop is no longer open to the public.

YzGyz

So it runs fine, sounds fine, feels fine, uprev datalogging says fine, only the gauge is saying otherwise? Could just be the gauge.

Boost leak?

Id try a different wideband gauge all-together to determine if the problem is within the vehicle/tune or the instrument.

I'm personally leaning towards everything is fine except my Innovative AFR gauge. It's a few months newer than the BP kit install. Any suggestions that wont break the bank?? I'm back in school so i"m poor again.

YzGyz

Crazy thought, but you sure your Injectors are okay?

Any chance to move the Sensor to the other bank and see if you get the same readings?

Are you saying I should take the driver side o2 sensor and put it into the passenger side bung Ave vice versa for the passenger side? I dint understand how this helps figuring out why my Innovative AFR gauge problem.

I'm thinking I might buy the same MTX-L and just plugging her as I already have everything wired for it.

YzGyz

I have/had a similar issue. My AFR fluctuates a lot too. The first problem was my fuel pump was going bad. After I replaced that, she ran good for a while then started acting up again. I found out that my MAP sensor needs to be programmed to read boost.


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Shasha pointed me in the right direction. I had a leak pre O2 sensor so I was getting in accurate AFR readings. The leak was located where the exhaust pipe and turbo connect via v-band. I put some high temp rtv and it solved the crazy high and random AFR readings.

YzGyz

Glad to hear it got sorted, my suggestion would have also sent you down the same path, albeit a longer way. If you moved the AFR O2 to the other side (where you now know there isn't a leak) you would have seen normal AFRs, so then you would have known the problem is definitely on one bank and your guage is fine, and work back from there.

There isn't another side to put it on. It's a post turbo bung where my aftermarket O2 sensor goes. I looked around and did see any carbon. I didn't feel anything loose or out of place. My heat wrap and turbo blanket his all the signs of a leak. Yup, the Z forum rocks! I was chasing and snooping around not sure what the F I should doing. Lol.

Thanks all for the help.
YzGyz

That's where my leak is too. I didn't realize you dropped the downpipe or I would have suggested that when you texted me. Mine is still leaking. Someday I'll get it on a lift and fix it.

I didn't drop it. I only looked at it and gave it a good wiggle. It was solid. It was good for many many miles then one day I got crazy AFR.

YzGyz

That's really odd to develop a leak without taking the v-band off and breaking the seal. It took a bit of effort to break the seal at the turbo even after I'd removed the clamp.

Yup. That v band is pretty snug and takes a little umph to break. That and the sudden change in AFR is why I was so confused. All I did was an oil change. Prior to that was A blown fuse. Oh well, got her fixed and I'm driving around again.

YzGyz