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Discussion Starter · #1 ·
Hello yall.
Looking for some advice or anyone who may of had this weird quirk or issue with their car. So I have a 2014 Challenger RT with the 5.7 with a 6 speed. About a month or two ago I changed the stock spark plugs out for a fresh set I purchased a while ago. The reason behind the plug change at 58,000 mile mark was because the shop who did the dyno tune on the car said it was getting close just by visual inspection of the condition of the plugs. Also I had ran a can of boostane through the car for a race night and the boostane likes to leave the plugs orange cause of the MMT used in it. So I put a set of Autolite plugs I purchased a long time ago for the car and I gapped them to 0.043 which is the stock gap. After the plugs changed it started and ran fine and then one day I noticed a slight hesitation or miss at 2500 rpm. It doesnt happen at any other RPM and there is no CEL. When this happens, I have a wideband installed, the AFR will bounce from normal to 15.9-16.9 and beyond. So I hooked up the HP tuners to see what was going on and there were "misfires" in multiple cylinders. So I thought I got some bad plugs, it happens. I went and bought a set of NGK iridium IX's and gapped them to the recommended 0.043 in. I installed and it fixed the issue somewhat. After hooking up the HP tuners to it again it only saw "misfires" in 3 cylinders. So I am not sure if i need to check the gap on the plugs again or what. Any advice would be helpful. If i cant figure it out i will assume its a tune related issue, which i wouldnt think so cause nothing has changed on the car since it was tuned, and contact the shop that tuned the car and see if they can do remote tuning or if i need to get back on the dyno to get it resolved. Thanks everyone and be good out there.
 

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I had random misfire no one cylinder responsible pretty much sounds close to your situation so I finally swapped out the coil packs and the problem disappeared, got the heavy duty coil packs from RockAuto. They carry many brands of coil packs including the Mopar, but the best warranty was Blue Streak and they were cheaper than the Mopar. I did a lot of research on the coil packs because there is no service interval in the shop repair manual regarding them like they will last forever, but they won't. Changed mine at 65,000 miles and the engine is running smoother now. Ry
 

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2012 Challenger R/T plus, 6spd
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What you could to to test is move the coil packs on the misfiring cylinders to others spots in the engine and see if the issue follows. There is nothing specific about which coil packs go with which cylinder.

I haven't replaced mine yet but maybe I should, I have over 150K miles now!
 
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What you could to to test is move the coil packs on the misfiring cylinders to others spots in the engine and see if the issue follows. There is nothing specific about which coil packs go with which cylinder.

I haven't replaced mine yet but maybe I should, I have over 150K miles now!
I just went ahead and replaced all 8 coil packs and that was after much research and running across one horror story of a guy testing his until one of the coil packs completely failed and took out his engine control module with it. It is not that major of an expense to change the 8 packs to brand new, unless you went the the super packs, but they only benefit racing setups and they do not last as long either. If you have 150K miles on yours you'll probably see not only your engine running smoother but probably renewed performance as well.
 

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It couldn't hurt!
 

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Discussion Starter · #7 ·
Hey everyone. So I did move one of the coilpacks to the other side of the motor, from bank 1 to bank 2, and the misfire did not move. The cylinders that have the misfires do not really show a pattern either so maybe replacing the coil packs and checking the torque on the intake manifold bolts may be the next step to see if the issue resolves it self. Just strange that the HP tuners Scanner detects the "misfires" but no CEL appears. It is a big enough issue that the AFR reads it and you can feel it while driving the car. I appreicate the help and advice and i will go from here and let yall know what happens.
 

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2020 Dodge Challenger Hellraisin Scat Pack
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Hey everyone. So I did move one of the coilpacks to the other side of the motor, from bank 1 to bank 2, and the misfire did not move. The cylinders that have the misfires do not really show a pattern either so maybe replacing the coil packs and checking the torque on the intake manifold bolts may be the next step to see if the issue resolves it self. Just strange that the HP tuners Scanner detects the "misfires" but no CEL appears. It is a big enough issue that the AFR reads it and you can feel it while driving the car. I appreicate the help and advice and i will go from here and let yall know what happens.
Some misfires are normal. Even the best engine doesn't fire each cylinder perfectly every time. What is looked for is too many consecutive misfires rather than just one or a few every so often.

That the CEL remains dark suggests the scan tool can obtain the misfires but these are raw not yet run through the software algorithm that decides if the misfires are CEL worthy.
 

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If your car is tuned, that could be it. My car also has a slight glitch, usually cruising at about 35 mph. It’s very subtle, almost like you let off the gas and then back on it again. I’ve never looked at the data while it happens but I wouldn’t be surprised if the afr goes wonky when it happens. I’m pretty sure it’s tune related because when the tune is taken out it doesn’t do it.
 

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Discussion Starter · #10 ·
Hey everyone. I hooked up the HP Tuners software to the car today and drove it to see if could catch anything that might tell me if this is a mechanical or tune related issue. So while driving in the trouble zone (2000-2500 rpm), a CEL finally showed up. A P113E and a P113D. I looked online and saw these were O2 codes. I have a feeling the O2s wont fix the problem but they are just an inidcation that something is not 100% right. I also caught some misfires in cyliner 7 and 8 as well on the VCM scanner. I think the approach is to replace the intake o rings, check the plugs for excess fuel and gap and contact the shop that did the tune on the car. I will post the pictures below. I am about 95% sure its not an injector issue since the pulse width values seem to nominal and all within an acceptable range. Any further input would be great but thats the plan at the moment.
283087
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If your car is tuned, that could be it. My car also has a slight glitch, usually cruising at about 35 mph. It’s very subtle, almost like you let off the gas and then back on it again. I’ve never looked at the data while it happens but I wouldn’t be surprised if the afr goes wonky when it happens. I’m pretty sure it’s tune related because when the tune is taken out it doesn’t do it.
After having my 5.7 dyno'ed, I have just the opposite. When I step on it at 35, the engine screams with no hesitation at all.
 
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