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17 gt pp missfire

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Hello everyone I recently noticed my 17 gt pp has a misfire, it is Lund tuned with a jlt intake and catback. I cleaned the maf and put new plugs. The plugs that came out look fine. Its not throwing any codes I am stumped I know it is missing it is very noticeable. Has anyone had this issue? I noticed I was not running the o2 tune from Lund for the last year. I still have cats so I put the o2 tune back on. Lund says that shouldent matter. It was like that for a year and all of the sudden started missing. I Datalogged and sent to lun so just waiting to see what they say. But I might as well put it back to stock and take it to ford an cross fingers they help me out? SOS!
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Returning it to stock will probably fix the issue .Ford can't fix what isn't broken (assuming they won't deny you because of the tune anyway).
 
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Thanks for the replys.. I hope not, I am going to return it to stock in the morning and see what happens. Still no word from the data log. I have some maf cleaner can i use that to tell if the intake is cracked?
 

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Hello everyone I recently noticed my 17 gt pp has a misfire, it is Lund tuned with a jlt intake and catback. I cleaned the maf and put new plugs. The plugs that came out look fine. Its not throwing any codes I am stumped I know it is missing it is very noticeable. Has anyone had this issue? I noticed I was not running the o2 tune from Lund for the last year. I still have cats so I put the o2 tune back on. Lund says that shouldent matter. It was like that for a year and all of the sudden started missing. I Datalogged and sent to lun so just waiting to see what they say. But I might as well put it back to stock and take it to ford an cross fingers they help me out? SOS!
Putting it back to stock won’t help you at all.

Once you have flashed a tune, you have essentially tampered with the vehicle systems - and most importantly, you have reset the Ignition Key Count. It’s been discussed numerous times on this site that once a Tune has been implemented, Ignition Key Counts are wiped - and if trying to flash back to stock tune, again Ignition Key Counts are wiped. So when Ford sees your vehicle has say 10k miles on it and say only 20 IGN Key Counts... well, the math is rather simple and there’s no way a vehicle with accrued miles has such a low key count.

If you need further explanation or more details about Ford’s Warranty wording, see here where I posted and attached additional info on a similar thread:
https://www.mustang6g.com/forums/th...-claim-denied-for-a-tune.119111/#post-2496076
 

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Trust me I know but the guy that worked there as the service advisor had a mustang with full exaust and tune. He told me to put it to stock before I bring it in so they can look at it. We'll see.. Cars only got 8k miles on warenty
 
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Best budz with the service manager hahahaha uhoh ya im probably screwed on the warenty work but it's my only car my daily driver. Put every cent I have towards it. Can ford get into the computer with a Lund tune on it? Or is it locked?
 

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Best budz with the service manager hahahaha uhoh ya im probably screwed on the warenty work but it's my only car my daily driver. Put every cent I have towards it. Can ford get into the computer with a Lund tune on it? Or is it locked?
They aren't going to touch your car for driveability issues with a tune installed. They Will charge you and flash it to stock.

Not to beat a dead horse but, tuning a car under warranty is a risky game. At least get some miles on the car to ensure any early infant mortality defects will crop up before introducing a new variable like a tune.
You have to accept the risk that you may be on the hook for any and all failures.
 
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Got my data log back from Lund this is what they said

Chris, this log you sent in shows no signs of misfire. Fueling is well within the range it needs to be and the results from this log are what I would expect from this combo.

Do we have any codes coming up or have we seen a flashing check engine light?

No codes no engine light
 
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Lund sent a tune today and told me to do a crank relearn but it dident help still missing. Sent a video and another 2 min log of it missing so we'll see. Not alot but enough to notice. Could my cats be kind of clogged? Can they tell if the coils are OK from data log? Still missing enough to jerk on miss at low rpm even on Freeway in 6th gear I can feel it. Only other thing I would thin it to test the coils and scope each cylinder.
 

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So I had my buddy that works for snapon use his scanner we found misfires in 123&4. Strange right? One side, passenger? So I'm thinking it's the baffles that open and close in the intake manifold that are stuck or broken causing a low rpm misfire. Only misses under 3500 not under load 1234. Coils good injectors good.
 
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I did go back to stock today, before finding out about the 123&4 misfire must not be missing enough for Ford to throw a code
 

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yeah the IMRC(intake manifold butterflies) being stuck could also be the issue since its all in 1 side.
 

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Putting it back to stock won’t help you at all.

Once you have flashed a tune, you have essentially tampered with the vehicle systems - and most importantly, you have reset the Ignition Key Count. It’s been discussed numerous times on this site that once a Tune has been implemented, Ignition Key Counts are wiped - and if trying to flash back to stock tune, again Ignition Key Counts are wiped. So when Ford sees your vehicle has say 10k miles on it and say only 20 IGN Key Counts... well, the math is rather simple and there’s no way a vehicle with accrued miles has such a low key count.

If you need further explanation or more details about Ford’s Warranty wording, see here where I posted and attached additional info on a similar thread:
https://www.mustang6g.com/forums/th...-claim-denied-for-a-tune.119111/#post-2496076
True, hopefully car runs OK in stock mode, put a few k miles on it and make alot of pointless short trips in the area to jack that keycount back up. Even if its driving around the block, shut car off, Start engine and rinse and repeat.. Do that 15 times a day for a few weeks along with the normal driving...
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