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Discussion Starter · #1 · (Edited)
Whats up guys. I've had my ST for about 3 years now (57k) and about 8 months ago I had a set of misfires while stage 3 strat tuned. Before that every once in a while when I would get on it the car would about **** on itself. I'd get going then all the sudden the RPMs would pretty much freeze and it would kinda sound like it was limiting itself. So I'd let off and drive like a grandma. Well that happened a few months later and I got a few misfire codes. Ended up swapping plugs and going back to stock for the time being.

Well this morning on my drive to San Antonio I ran into the same issue (note this is like 8 months of being stock with no issues). First I got a check engine for misfire for about 2 seconds (which I barely noticed). Then I was passing someone and that same thing happened where about quarter to half boost and the RPMs would just kinda **** on itself and limit. So I let off and drove the rest of the way fine. I would say this is just the effects of LSPI BUT most of the time this has happened in a lower gear higher RPM.

So what could be the issue? Maybe injectors?

(sorry for any typos)
 

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Discussion Starter · #3 ·
I for sure will but crazy since they were brand new stock plugs that I swapped 8 months ago and gapped them to the aftermarket spec just because.
 

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I for sure will but crazy since they were brand new stock plugs that I swapped 8 months ago and gapped them to the aftermarket spec just because.
Plugs should be checked every oil change/5k miles in our cars honestly. They get whacked out of gap so easy.

Edit: Start there since it's a cakewalk to check. If that is fine and they are gapped correctly .025 -.026 (Stratified's recommendation) then make sure they aren't fouled and maybe work with your tuner on the issue?
 

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Discussion Starter · #5 ·
Plugs should be checked every oil change/5k miles in our cars honestly. They get whacked out of gap so easy.
Yeah but I've never heard anyone have my issue just because of gapped plugs. BUT I will check this weekend, I had to order some tools.
 

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Yeah but I've never heard anyone have my issue just because of gapped plugs. BUT I will check this weekend, I had to order some tools.
Neither have I, other than the miss issue. If it misses and throw your engine into freak out mode it does a lot of weird stuff, I edited my post.
 

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Discussion Starter · #7 ·
Neither have I, other than the miss issue. If it misses and throw your engine into freak out mode it does a lot of weird stuff, I edited my post.
I am currently not tuned. After I had the last issue I went back to stock downpipe and stock tune for the time being. I planned on bolting back on next month once I got a truck.
 

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I am currently not tuned. After I had the last issue I went back to stock downpipe and stock tune for the time being. I planned on bolting back on next month once I got a truck.
Ah, well in that case check plugs then do some stock datalogs? I imagine you still have an accessport and flashed to the "stock" map when you unbolted. Maybe it'll show something whacky going on? If you see some crazy corrections or something maybe it'll point out an underlying issue.
 

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Discussion Starter · #9 ·
I do have afterfires sometimes when decel on stock tune. Another reason I was worried about the injectors.
 

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Discussion Starter · #10 ·
Ah, well in that case check plugs then do some stock datalogs? I imagine you still have an accessport and flashed to the "stock" map when you unbolted. Maybe it'll show something whacky going on? If you see some crazy corrections or something maybe it'll point out an underlying issue.
I'm 100% stock tune. The first time had me super scared to I completely unmarried it haha. But once I get back home next month I'll atleast put stage 0 to see if something wrong, that is if im still running into issues.
 

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I'm 100% stock tune. The first time had me super scared to I completely unmarried it haha. But once I get back home next month I'll atleast put stage 0 to see if something wrong, that is if im still running into issues.
I'm pretty sure when you unmarry it, it puts you on a clone of the stock tune, it isn't the real stock tune. So you should be stage 0 right now. Just marry the AP again and run a log and hopefully it'll point to an easily fixed issue. The Accessport is a monitoring tool at heart, so it can help even on stock cars to find issues! Better than paying the stealership to hook it to a computer and run codes or something.

Edit: Let us know!
 

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Discussion Starter · #12 ·
I'm pretty sure when you unmarry it, it puts you on a clone of the stock tune, it isn't the real stock tune. So you should be stage 0 right now. Just marry the AP again and run a log and hopefully it'll point to an easily fixed issue. The Accessport is a monitoring tool at heart, so it can help even on stock cars to find issues! Better than paying the stealership to hook it to a computer and run codes or something.

Edit: Let us know!
I will for sure!
 
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Discussion Starter · #13 ·
I'm pretty sure when you unmarry it, it puts you on a clone of the stock tune, it isn't the real stock tune. So you should be stage 0 right now. Just marry the AP again and run a log and hopefully it'll point to an easily fixed issue. The Accessport is a monitoring tool at heart, so it can help even on stock cars to find issues! Better than paying the stealership to hook it to a computer and run codes or something.

Edit: Let us know!
Checked all my plugs today. Every single one was the perfect color and only one was off a bit so I gapped it back down. I'm going to load my AP on the car later today and see if its an AFR issue. I have a feeling my sensor is at the end of its life.
 
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Checked all my plugs today. Every single one was the perfect color and only one was off a bit so I gapped it back down. I'm going to load my AP on the car later today and see if its an AFR issue. I have a feeling my sensor is at the end of its life.
Fingers crossed that that's the issue and not something more serious
 

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Discussion Starter · #15 ·
Fingers crossed that that's the issue and not something more serious
Yes an o2 would be an easy fix if thats the case, my buddy recently has the same issue
 

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Discussion Starter · #16 ·
AFR looks good. Still probably going to replace both sensors. Haven't had any more issues though.
 

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AFR looks good. Still probably going to replace both sensors. Haven't had any more issues though.
I had the same problem. Make sure it's no an intake problem. Aka the black think on the back of the intake is securely put in. I had the same problem. It gets worse when you add more power. Enough to throw a po300 code which is just a general misfire. Mine doesn't do it as much now but I'm starting to lean to that it could be the intake pipe superheating my air. Though I do want to replace all the coil packs. They are only like 25 dollars a piece. @Tursko maybe we can work together on a solution. My tuner said it has to be an ignition problem. Aka Alex from Stratified. Plugging in the black thing on the back has resolved 85% of my misfire problems.
 

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Discussion Starter · #18 ·
I had the same problem. Make sure it's no an intake problem. Aka the black think on the back of the intake is securely put in. I had the same problem. It gets worse when you add more power. Enough to throw a po300 code which is just a general misfire. Mine doesn't do it as much now but I'm starting to lean to that it could be the intake pipe superheating my air. Though I do want to replace all the coil packs. They are only like 25 dollars a piece. @Tursko maybe we can work together on a solution. My tuner said it has to be an ignition problem. Aka Alex from Stratified. Plugging in the black thing on the back has resolved 85% of my misfire problems.
I haven't had anymore issues really. I am running a stage two tune from Strat. But Ill still check
 

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I haven't had anymore issues really. I am running a stage two tune from Strat. But Ill still check
So what did you do to fix the problem then? Was it the o2 sensors in the downpipe?
 

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Discussion Starter · #20 ·
So what did you do to fix the problem then? Was it the o2 sensors in the downpipe?
Just made sure the plugs were gapped properly and put a new tune on it. Haven't seen anymore issues but I don't daily it anymore, just got a truck.
 
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