misfire? need help and suggestions

[Danishp97]

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Hello everyone. I bought the car 8 months back roughly 24,000 kms on the odo.
Did an oil change, filter change etc. car already had a custom stage 2 tune when I bought it. Previous owner had done spark plugs (oem gapped properly) when tuning the car at 20,000 kms.

After I got the car I did injectors and coils together as preventive maintenance. Everything was fine. However 2000 kms post all this I blew one fuel rail. Followed by the second one a week later.
We installed new fuel rails. Car was driving fine until 500 kms later injector 8 started to leak from TOP.
Temporarily put the 8th injector from my previous injectors that were taken off the car and called in for a replacement. Everything was okay and i went for a good 200 kms drive post which when I got home the car started to sound like misfire at idle. Decided not to drive until the replacement injector 8 is here. Got the replacement injector, installed it, but the misfire like sound at idle is still there. Scanned for codes car has no codes. Misfire counter reads 0. Cylinder smoothness test shows Cylinder number 6 running rough. Value is somewhere near 5. I swapped the coils and plugs from cylinder 5 to cylinder 6 to see if there’s any difference but no difference as such. No codes, and smoothness test shows cylinder 6 running rough. Today I went for a drive again, clocked 282kmph easily without any hiccup, car pulls proper. Only when I stop and it idles I can hear my exhaust pop intermittently and feel a vibration/hiccup of sort under my seat.
One thing I realised that when I cold start the car it does not misfire until the cold start settles.

Is it a vacuum leak? Failing lpfp? A little lost at this point as it drives PROPER.

Car’s odo is at 28,000 kms and it’s a 2013 car. Any help is appreciated!

[Mr. M6]

had same sound, was leaky injector & replaced all my injectors.
no codes was there.

[Amitt]

Did you code the new injectors?

[Danishp97]

Originally Posted by Amitt

Did you code the new injectors?

Hi yes! I had. My issue is fixed, my injectors were installed without crush rings/O rings.

[SCD-1983]

Originally Posted by Danishp97

Hi yes! I had. My issue is fixed, my injectors were installed without crush rings/O rings.

Seriously? I hope it was performed by a shop and they stood behind such a mistake. Just wow, installing injectors without seals and connecting elements is a huge error. I’m happy you found out and it’s running ok now 🙏

[Molotov1903]

Originally Posted by SCD-1983

Seriously? I hope it was performed by a shop and they stood behind such a mistake. Just wow, installing injectors without seals and connecting elements is a huge error. I’m happy you found out and it’s running ok now 🙏

Insane, im glad it didnt turn into a disaster 🤣👍