CEL misfire during hard acceleration

[Ragingred]

I know there a lot of threads on this but a lot that I read either are years old or they go completely off topic. I have 2019 Raptor with 48k miles. Just a month ago I had a Cobb FMIC, AMS turbo inlets, 180 thermostat, Ford performance cold plugs and an MPT tune run through a SCTX4 tuner installed. I have been running the truck hard and no issues until today on the highway when I accelerated hard to pass the whole truck started to shake and CEL was flashing. Scan shows PO301 cylinder 1 misfire. After pulling over and turning it off, it sat for about 10 mins as I looked over everything. Got back in and it started up with no CEL. Continue my 2.5 hour drive with no CEL. Should I start with checking the plug of cylinder 1? Is this common with tunes? Thanks in advance

 

[vudu_raptor]

Im having near identical issues and had your instance happen twice before taking it in.. Bought my 2019/Gen2 in March 23 with 38k miles.
Slapped on my old truck's parts (COBB FMIC, , air oil seperator, 170deg SPD thermostat, ROUSH CAI, Stage 2 Goosetune) and started noticing weird ticks about 2 months later. the PIDs all show good numbers. The Dealership did the Cam Phasers at 45k miles hoping it would resolve the random misfires. I was getting P0300 (RDM misfire) only on long road trips at normal speeds.

The dealer had my truck for a month and couldnt nail it down. Changed Sparks, coils, dropped the exaust (noted a lot of unburnt fuel in my Cat), checked all fuel system sensors and swapped injectors. They ended up putting all my parts back on. I've noticed it misfires at idle or under hard load only and is worse in humid/wet weather. Normal driving is ok. Throttle >65% it starts getting choppy. Since last week I've replaced the thermostat back to stock 195deg, and re-did all the intake connections... I noticed a kink in my PCV hose, kink in the blowoff valve hose return line, and a crushed intake pipe from the dealer's tech losing his patience, boiled it and mushed it back to normal... I'll replace the MAF in the airbox becuase why not, and set the Plug gap to a recommended 0.026" and get back to you.

 

[xjjosh]

I had the same thing with aftermarket spark plugs. Bought new stock ones with correct gap and it hasn’t happened since.

 

[vudu_raptor]

I had the same thing with aftermarket spark plugs. Bought new stock ones with correct gap and it hasn’t happened since.

Good to know. I put sparks on in July and its been misfiring since May. Dealer said they found a cracked plug and want to change coils. I gave them the go ahead. I'll have them gap them tighter at (0.026) and new coils wont hurt. I'll take the old ones on my baja trip as spares. Second thing is injectors if this repair doesnt work. I'll update tomorrow.

 

[vudu_raptor]

I know there a lot of threads on this but a lot that I read either are years old or they go completely off topic. I have 2019 Raptor with 48k miles. Just a month ago I had a Cobb FMIC, AMS turbo inlets, 180 thermostat, Ford performance cold plugs and an MPT tune run through a SCTX4 tuner installed. I have been running the truck hard and no issues until today on the highway when I accelerated hard to pass the whole truck started to shake and CEL was flashing. Scan shows PO301 cylinder 1 misfire. After pulling over and turning it off, it sat for about 10 mins as I looked over everything. Got back in and it started up with no CEL. Continue my 2.5 hour drive with no CEL. Should I start with checking the plug of cylinder 1? Is this common with tunes? Thanks in advance

Ragingred,

TLDR: Dealer ordered new spark plugs (told them to gap them tighter at 0.026), coils/boots, one port injector on bank 1 they suspected was not at 100%, and a fuel pressure sensor.
I let the engine warmup and rode it HARD on the way home from the dealer... --> No misfires... We all think it was a combination of several small things that compounded over time. Cost: $1450 minus some random warranty savings they were able to get me.

Did the same upgrades you did (save Goostuned with COBB tuner vice SCT) in June 23. July I started seeing this issue. They changed the Sparks after mine were only a month old, changed the fuel px sensor on Bank 1 I think, and did the Cam phaser job with VCTs as well. This HELPED but did not solve the issue. I ran those sparks until today. One spark had a crack in it and messed up the boot. But I was getting a Random misfire... FORD SOLD US BAD PLUGS. Somehow the truck wasn't throwing a code and the ECM was still trying to figure it out. That apparently messed with the learning so bad it was getting chaotic in there. I flashed the tune before taking it in, they did the above work, now its purring. Weird as hell.

Hope this helps. A million variables could cause a Mis. Happy hunting.

 

[Granelli]

Same issue, 120k hard miles on the truck (2018). Stage 2 goosetuned. Cleaning the Map sensors helped, gapping to .026 cured all signs of misfire and the truck runs like it has since low mileage.