AFR going nuts 1day after dyno tuning

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EKJOE

New Member
AFR going nuts with video

Well, This happened 1 full day after spending 5 hours on a mustang dyno with a professional tuning my car.

It ran like a beast for that 1 day. At the end of the first day I did a hard pull off a stop light...WOT hitting VTEC but I wasent redlining. After I slowed down and kept a steady throttle I noticed my AFR was going nuts! Swinging between 11 and 18 wildly and this is under light throttle....The TPS read 5 and I was in 4th gear 3200 RPM while it was doing this.

The motor started to jerk and bog and cut out....Im like WTF is going on here? Its a fully build LS/VTEC with 1800 miles on it, 93 octane and mobile1 syn10/30.

Now when I go WOT it runs real rich,Idle seems to be ok...It goes back to 14.7 half the time and the other half it runs rich in the 12's. Under light throttle cruising well...........

Heres the video.
YouTube - LS/VTEC AFR problem 1 day after Dyno tuning
 
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I have 100% faith in my tuner. I dont believe this is his fault...I do believe this is a physical problem somewhere that just happened to show up after the car was tuned.

Anyone have any ideas?? Im thinking TPS.
 
sounds like TPS, throw a multimeter on it.
 
So I turned on the ignition and checked the TPS and it read correct.

I unplugged the TPS and re plugged it in, I also unplugged the map sensor and re plugged it in.

I went for a 10 mile drive and its stopped doing it....WTF?
 
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