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WarrenBoostit

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Hey everyone, I own a 2018 58k mile SHO with the gearhead AO tune, intercooler and HPFP, as well as a few other common mods running 93 Octane, that I actually purchased from another member of these forums. Today I was driving in very cold temps (10 degrees Fahrenheit) when I noticed that on pulls that brought the car over 0 PSI, the KR reading in degrees would dip into the negatives, usually around -0.2, but even down to -2.25, and seldom positive, but occasionally I'd see +0.5, anything else with negative PSI was 0. I'm hoping that Fords trend of using negatives to mean adding timing and positives for pulling timing applies here; the car doesn't feel down on power (I don't think), the OAR is staying at a steady -0.96 with the intake pressure at -10.5 PSI idle(already had to replace the MAP sensor once so far so I know that's probably accurate), nothing really seems out of the ordinary yet, not hearing any pings or leaks, other than it seems to be hanging on to 4th gear a bit longer than I remember.

Would anybody have some insight as to what may be going on here, and how worried I should be? I should probably collect logs; my guesses are it could be a bad knock sensor (the prior owner removed the under engine cover because it was triggering it when it flapped in the wind), oil in the intercooler, a vacuum leak (please god no), winter gas, or maybe the much increased wind pressure today and cold temps had an impact? I feel like many of these would've triggered codes or at least changes in my OAR, temps and/or intake pressure.

I'm new to SHOForum, though I am well read on the previous owners posts here, and it really seemed like this car never gave him trouble, and on its good days it really drives amazing, however in the 5 months I've owned it I've already replaced the MAP sensor after being sent into limp mode, replaced the battery as the prior somehow was murdered in a week and a half of not driving, dealt with some windows freezing and being unable to roll down, am noticing a slight bit of shinyness that hopefully is just condensation on the outside of tubes leaving the air filter, and am gearing up to do a full rotor replacements after debris caught in my rear brake gored out the rotor. I feel like I'm receiving the crash course in Taurus/SHO issues, and am really looking for a bit of good news or advice.

Thanks!
 
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WarrenBoostit

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Update, hit +2.25 in 6th on a long pull in 27 degree weather, something to be concerned about? Symptom of maybe a vacuum leak or weak injector? Or even something as simple as a clogged intake filter?
 
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SM105K

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Update, hit +2.25 in 6th on a long pull in 27 degree weather, something to be concerned about? Symptom of maybe a vacuum leak or weak injector? Or even something as simple as a clogged intake filter?
I wouldn't worry about it. If you are see +4 to +5 I would start thinking about it. I see +3 regularly on 91 octane here in AZ.
 

WarrenBoostit

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I wouldn't worry about it. If you are see +4 to +5 I would start thinking about it. I see +3 regularly on 91 octane here in AZ.
What's really tripping me up is that, although it makes perfect sense to be dynamically modifying timing, I swear in the same environment a month ago the KR reading never moved from 0, which also kinda makes me fear that the sensor wasn't working until now, and should have been pulling timing. Either way, I think the best path forward is an oil change, intercooler drain, filter and spark plug swap. I'm really thinking with the cold months oil has collected in the intercooler and it might be the cause for the readings.
 

SM105K

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What's really tripping me up is that, although it makes perfect sense to be dynamically modifying timing, I swear in the same environment a month ago the KR reading never moved from 0, which also kinda makes me fear that the sensor wasn't working until now, and should have been pulling timing. Either way, I think the best path forward is an oil change, intercooler drain, filter and spark plug swap. I'm really thinking with the cold months oil has collected in the intercooler and it might be the cause for the readings.
It is probably crappy fuel. It happens. Either way a good tune up wouldn't hurt.
 

WarrenBoostit

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E30 seemed to make the bad numbers appear less often, however I still saw 1.5 around 18 PSI I thought (I really should datalog this, since the cylinder it's happening at would be insightful). I've heard if E30 doesn't solve it it could be a scenario of false knock, though I'm not going to come to any conclusions or throw the wallet at it before I replace the EPP Gen2 Cold Air Filter and give it a good fluid change and intercooler drain.
 

WarrenBoostit

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Yikes, on e30 at a stop light launch with a filter change I momentarily hit +6.59. Time for logs...
I don't think Matt from GH would be too keen on supporting someone who hadnt paid for the tune initially, but I might have to send him a message if I can't figure it out
 
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WarrenBoostit

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Also, a separate question: if I can't figure out what's causing the brief KR positives on e30 on the AO tune, would it be entirely unwise to move to an e30 tune like I was planning to do this summer? I'm assuming if I am unable to meet the octane demands on AO with e30 when I get around 18 psi, being tuned for e30 will be even more risky?
 

SM105K

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Also, a separate question: if I can't figure out what's causing the brief KR positives on e30 on the AO tune, would it be entirely unwise to move to an e30 tune like I was planning to do this summer? I'm assuming if I am unable to meet the octane demands on AO with e30 when I get around 18 psi, being tuned for e30 will be even more risky?
You are entirely over thinking it. If it just started happening, it is/was probably bad gas. I would go to another gas station when you fill up and see if that clears it up. If you think +2.5 is bad, you would be horrified what a stock tune does.
 

WarrenBoostit

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You are entirely over thinking it. If it just started happening, it is/was probably bad gas. I would go to another gas station when you fill up and see if that clears it up. If you think +2.5 is bad, you would be horrified what a stock tune does.
This is reassuring, I do need to remind myself that MN has truly horrible gas in the winter, especially at stations at the bottom of hills that the snowmelt leaks into the underground tanks.
 
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