Wideband (AEM Eugo) problem

[krummel21]

When driving around town the wideband works fine reading everything as it should but when I go WOT the A/F go to 18 and I haven't changed anything since my tune a couple months ago and the same gauge was reading 11's. What would cause this? Log 19 is the one showing the wideband problem and 14 is the same setting a couple months prior.

Thanks,
Krummel21

 

[1stGenRocks]

make sure you dont have any exhaust leaks before the sensor is the first thing that comes to mind. I know my buddies LM1 was really sensitive to any exhaust leaks before it. especially if theyre before the turbo because then its an even bigger leak under boost.

 

[CanadianTSi]

Make sure the vacuum line didn't come off the FPR.

 

[krummel21]

Do any of you think that it might be the sensor going out?

I haven't touched the exhaust since I installed the turbo (run 14), I checked the exhaust and didn't notice it being loose.

Studid question is the stock FPR attached to the fuel rail?

Teh front o2 sensor in run (19) was reading a/f fine does this point to anything?

Thanks,
Krummel21

 

[2gAWDTalon]

Alot of people talk about exhaust leaks... when my car has even the smallest of exhaust leak I can hear it well, from the drivers seat! If you had a exhaust leak I am sure you would hear it...

Did you post this in the DSMLink forums? Obivously you have link...

Edit: BTW THe car is not knocking... so I cant imagine you really being at 18+ afr.
Anyone here that has had a WB sensor go bad what were the symptoms?

 

[krummel21]

I called bosch and asked what they thought and sence it was reading fine when not under WOT he thought it was because I have it mounted in the rear O2 position and this is behind the flex section in the exhaust. Which must be positioned in a way that air is escaping. This sounded pretty plausable. I did have to bend the exhaust up a little there when installing the 3052.

I'm going to have a bung welded before the flex sometime this week hopefully that'll fix it.

 

[CanadianTSi]

If you have a leak in your exhaust pre-sensor then that will throw off your readings.

You don't want the sensor too close to the turbo, the Instructions say 36" away.

 

[drewvr4]

have you run leaded gas in it? thats been known to make the sensors go out on those quick.

 

[krummel21]

no I've only run 92 octane or better. Is 36" after the flex section?

 

[drewvr4]

no I've only run 92 octane or better. Is 36" after the flex section?

off the turbo flange 36"

 

[krummel21]

Sorry I ment from the turbo flange is it less than 36 inches to the flex pipe or could it safely be mounted before the flex section?

 

[krummel21]

Anybody know how to test the sensor to see if it's bad?

 

[8urv8]

Hey, did you ever figure this out. I'm having the same problem with my car. All of the sudden, the wideband is reading way lean (18:1). When I log, I get no knock and the a/f on dsmlink is reading what it used to read but the wideband is reading super lean. I know I've got a slight leak in the flex section but I didn't think that would throw the reading off that much.


Ryan H.

 

[blcknspo0ln]

Sounds like a bad sensor. I've killed 3 already. The best way to tell is turn the car on (don't start it) and watch the wideband. It should rich and then gradually go leaner and leaner until it goes to - - - (free air). If the wideband does that, then it's working correctly. If it doesn't, it means either the sensor is bad or the unit is bad (99% usually the sensor).

 

[8urv8]

Sounds like a bad sensor. I've killed 3 already. The best way to tell is turn the car on (don't start it) and watch the wideband. It should rich and then gradually go leaner and leaner until it goes to - - - (free air). If the wideband does that, then it's working correctly. If it doesn't, it means either the sensor is bad or the unit is bad (99% usually the sensor).

My wideband is like 3 month's old. I hope the sensor isn't bad. I'll check to see if the sensor swoops like you described.

 

[spyderturbo007]

When I developed a leak in my flex section my UEGO starting getting all funny too. At idle it would start around 14.7:1 and then slowly get leaner and leaner until it ended up around 17:1. At cruise it seemed to be pretty close, other than the fact that it bounced around more than it did before the leak. Also, at WOT it was reading about 2 AFR's leaner than it should have been. It was showing an AFR of 12.5:1 during WOT using the baseline DSMLink injector compensation which would hit the factory AFR of 9.5:1.

 

[8urv8]

When I developed a leak in my flex section my UEGO starting getting all funny too. At idle it would start around 14.7:1 and then slowly get leaner and leaner until it ended up around 17:1. At cruise it seemed to be pretty close, other than the fact that it bounced around more than it did before the leak. Also, at WOT it was reading about 2 AFR's leaner than it should have been. It was showing an AFR of 12.5:1 during WOT using the baseline DSMLink injector compensation which would hit the factory AFR of 9.5:1.

Yea I've got a leak in the flex section of my down pipe. I just figured this out today. I wouldn't think that a leak would cause that much of a problem at WOT. At cruise it's reading normal, at idle it's very lean and at WOT as soon as I start to spool it goes all the way lean and doesn't even show a reading on the wideband.

 

[spyderturbo007]

That's what I have found is the typical problems with the flex section leak. I ended up buying a brand new DP when I found out the last one was leaking, and guess what, the new one leaks right out of the box.

I'm going to just move the bung in front of the flex section since I'm getting sick of dealing with this crap. I don't care if I have to replace the sensor every year, it's better than replacing the DP every 3 weeks.

 

[8urv8]

Update. I found I had two problems. A leaky flex section and a bad sensor. The combination of the two was enough to drive me insane thinking there was something up with my car. Got a new turbo back and sensor, now everything is running like it should.

 

[spyderturbo007]

Good to hear.

You might want to use the new feature at the top of the thread and mark this as "Resolved". It's in the drop down menu entitled "Thread Tools".

 

[8urv8]

I don't know if that would be the proper forum procedure since the OP didn't say his problem was fixed. I was just shedding some light to others that may have had similar problem's as myself. It's good to know that you can do that though. Thanks.


Ryan