Aem Wideband Gone Bad?

[DSMULATOR]

Ok, so last year I installed the AEM UEGO wideband in the rear 02 sensor location and had no problems. I kept it in my shop all winter and pulled it in and out everyday. Let it idle and warm up to when the fans cycled and shut it down. Every morning it started up rich and I let it idle and it started sweeping around the 14.5-15 mark like always. I put it back on the road yesterday and it started showing real lean conditions. I checked DSM Link and none of the settings have changed, my front 02 sensor sweeps, but even at idle and start up the AEM is pegged at lean. Has anyone had any of these sensors go bad? I've got good fuel pressure, and haven't changed anything since last year. Any ideas?

 

[16gpoweredgsx]

It's possible that from a year of pulling the car in and out, starting it, letting it warm, then shutting down, the condesation in the exhaust fouled it out.

 

[talonalex92]

That shouldnt be a problem if you installed it at the angle they said too?

 

[DSMULATOR]

I took out the rear sensor, since I had no cat, and put it in its place. It worked fine for me all last year..

 

[DSMULATOR]

How about the MAF translator messing up the airflow calculations?

 

[DSMULATOR]

And if my A/F was truly that lean, wouldn't I be getting some knock? Because it runs fine, I boosted it once and then shut it down and parked it because I didn't want to melt anything, but my CEL didn't flash from knock.

 

[V8notENUF]

Have you ever ran leaded fuel? Pretty common to go through those bosch sensors about once a year.

 

[1992awdlaser]

Does it show ---?

 

[DSMULATOR]

I wanted to run leaded race fuel but never did. It goes all the way to lean and shows '---' and then when driving sometimes it will jump to like 13 and then oscillate back at 15 like normal, but once i hit coasting fuel cut it will stay at the dashed lines for a while. Now when I start it it starts at 15 and instead of dropping to 10 and building back up as it warms, it drops past 18 and then goes to '---'

I just did a boost leak check and the only leak is at the #1 injector insulator to the head, but I have no fuel pressure in the rail and once i push the injector down it stops, its very minor. I don't want to buy a bosch sensor if I don't have to but am hoping that's all it is. I checked the MAF and all the settings are the same as last year and correct for the 2G. It is getting a signal because the LED's light up when I turn the key on.

EDIT: I also pulled all the plugs, compression checked it and checked to see if they were burning antifreeze. Everything was fine.

 

[1992awdlaser]

From what I have seen the sensor is bad if it either shows the --- at all times or if it is giving inaccurate readings at all times. On your Dsmlink do you have the air/fuel estimate settings right? The elavation and injector size is what I am talking about. If so, what does the air/fuel estimate show? Post a log if you can with air/fuel, o2 sensor, and wideband being captured at least.

 

[DSMULATOR]

From what I have seen the sensor is bad if it either shows the --- at all times or if it is giving inaccurate readings at all times. On your Dsmlink do you have the air/fuel estimate settings right? The elavation and injector size is what I am talking about. If so, what does the air/fuel estimate show? Post a log if you can with air/fuel, o2 sensor, and wideband being captured at least.

For some reason I have never been able to get the A/F estimates in DSM Link to match my wideband. I have 750cc injectors with the deadtime at 315, global at 35%. I had the timing, fuel, and airflow sliders professionally tuned at a dyno facility. I haven't figured out how to log the AEM in DSM Link. I tried going through the Link Wiki and setting it up that way but it didn't work for me, i probably messed up somewhere. I have ordered a new sensor and it will be in tomorrow.

edit: and I have the MAF translator set for 450cc injectors and do all the compensations thru Link.

 

[1992awdlaser]

In Dsmlin open it and hit F4. When the values come up highlite air/fuel. Then click on props and put in your injector size and elevation. The air/fuel estimate should be close to the wideband but won't be exact. Your global should be -40% or you will probably have to adjust teh fuel/airflow sliders more then normal. But if it is working for you keep it how it is and just keep that in mind if you run into a problem.

 

[DSMULATOR]

In Dsmlin open it and hit F4. When the values come up highlite air/fuel. Then click on props and put in your injector size and elevation. The air/fuel estimate should be close to the wideband but won't be exact. Your global should be -40% or you will probably have to adjust teh fuel/airflow sliders more then normal. But if it is working for you keep it how it is and just keep that in mind if you run into a problem.

Ok, I clicked on props and it was at 450cc and 0 usecs. I guess when I lost battery connection and reloaded the settings that didn't get changed or never at all. Anyway, I put in 750cc injector size. Is the deadtime of 315 (from the fuel sliders screen) the same in usecs, isn't there a conversion? And what is fuel specific gravity? do I put that in feet about sea level or what?

 

[1992awdlaser]

Leave the fuel specific gravity alone unless you run race gas. Then You can get it from the maker of whatever fuel you are running. They don't put those settings in when you buy Dsmlink so that is probably why they were set where they were. Yes you put the elevation in feet above sea level. And yes put in 315 for usecs. Any more questions let me know.

 

[1992awdlaser]

The fuel specific gravity is at .76 right?

 

[DSMULATOR]

yeah it is already set at .76

I don't have a field for feet above sea level. Is that just a 1G thing?

 

[1992awdlaser]

Sorry the elevation is under boostest. Do the same thing as air/fuel estimate just under boostest and it will pull up a window.

 

[DSMULATOR]

I put the new sensor in today and its back to normal operation. I guess next year when I store the car I'll take the sensor out and keep it in a dry place so carbon and condensation don't build up again. It was scary but I'm glad my pistons aren't melted.

Thanks for all the misc. help with the DSM Link stuff that I missed. The A/F in Link still doesn't match my wideband, but i'll hunt around the DSM Link forums and see if I missed anything else.

 

[Gamble97]

Those sensors are crap. I put mine in the rear 02 location on my 2g, drove it 2k miles on 93 octane and it went bad.

 

[1992awdlaser]

The air/fuel estimate should be close but it is just that an estimate. It won't be exactly the same as the wideband. And I would go off the wideband anyway. I just mentioned the air/fuel estimate so you could see how far off the wideband was from it. If it is off by a lot I would say the wideband sensor is bad.