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AFR Gauge trouble

M-Head

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Jan 27, 2010
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Yakima, WA
I've got an AEM wide band AFR that worked great last year, but 1st ride out, was going all the way lean at WOT. I would let off, and it would start reading again, then later, just showed three dashes most of the time. Checked the wash and it's good--I'm thinking it is the o2 sensor but wanted to see what you fine folks thought. Running straight 100LL and 10 lbs.
 

RobertTrivanovic

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You say wash is good but just make 100% sure it is, check your plugs too, last year on my N/A sled my ground wire on my boondocker box broke and it didn't work because of that so it was reading the stock map, went way lean. Something to check
 
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Snopro_69

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Mar 25, 2008
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100 LL KILLS sensors. Depending on your sensor placement an how much direct in the line of exhaust it is. Buddies 2010 m8 has lasted two seasons. My 2012 has went through 4 in 1500ish miles in 2 seasons.

Oh ya your symptoms are exsactly what mine do when they burn out. Ruined a trip for me first time cause didn't know what it was doing. Now I run dual egts too an watch then lots of time instead.
 
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007

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www.4seasons.com
100 LL KILLS sensors. Depending on your sensor placement an how much direct in the line of exhaust it is. Buddies 2010 m8 has lasted two seasons. My 2012 has went through 4 in 1500ish miles in 2 seasons.

Oh ya your symptoms are exsactly what mine do when they burn out. Ruined a trip for me first time cause didn't know what it was doing. Now I run dual egts too an watch then lots of time instead.

Not harping on you, but why would 100ll burn out sensors vs race gas? Seems this topic has been beat to death, but there is no real proof.
 

M-Head

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After I ruled out some type of air leak and fuel controller failure, I richened up the boost a half light and it ran like a top all day. I have a new o2 sensor, will install it and take it out this weekend. I'll let you all know. Thanks for the input!
 
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Snopro_69

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Mar 25, 2008
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The lead in the 100LL kills sensors plain an simple. If you read right on AEM instructions it tells you the life of sensors with be considerably less with the leaded fuel.
 

BigAir

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I think he was saying that 100LL will kill sensors faster than pump fuel, not race fuel.
 
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