Today while I was driving to work I noticed that the A/F on my wideband was acting screwy and then I started getting quite a bit of ST KR on light accelerations (and I do mean light, less than 1/4 throttle up to like 35mph hitting 2000rpms max during that time). Now everything was acting fine monday and then today comes around and this is happening. It is only doing it at part throttle though, at WOT its running 0 KR and 11.9 A/F. Accelerating from 25mph to 50mph at part throttle (less than a 1/4) my A/F jumps from 14.5 to 9 to 15.6 to 12 and then evens out and my KR will spike from 0 to 2.5 back to 0 and if I give it any extra gas (passing someone) it pops its head up again to .5 - 1.5.

I dont get it, no codes, no cel, same tune have not touched it since I got it dialed in about 3 months ago. I need to go under and check the header bolts and the wideband/cables but cant do that til friday, also need to do the oil and rear diff but again cant do that til friday (working 3:30am to 4:30pm is taking its toll). Anyone have any clue WTF is going on here?????

 

Did you fill up recently? Maybe bad gas? I had that happen once to me and couldn't figure out what it was. Turned out to be bad gas from the station. The only reason I found out was bc my friend works for wawa and told me the station got fined for bad gas that didn't meet the octane advertised.

 

I filled up last friday at a chevron by my office with 91 its been fine up til today

 

Guess I can try throwing a thing of octane booster in it but its only at a half tank right now

 

Truckin, wish I could help. I don't understand half the readings I get.

 

Well the AF is always changing but it has never dipped that low before on a light throttle, the thing that scares me is the KR, I dont need anything knocking, that just spells damage there...

 

Although it fully does not explain it I still think this sounds like contaminated fuel. It happened to a friends truck after the premium underground storage tanks were contaminated with diesel. Truck ran like *** had to have the tank pumped and flushed.

 

With your explanation (light throttle) I would guess you have an air leak . Are your knock sensor's enabled? Are you getting knock retarding? Just thinking out loud.

 

Yep they are enabled and thats the KR that I am getting now, I always monitor the ST KR. I guess I can go fill up the rest of the tank at a different gas station and see if it dilludes it a little.

 

Drain the gas into cans and use it in your lawn mower. lol....