3BOSH

hello again my most helpful mates <3
The first issue is that i have found different sources saying the g37 2010 engine is either direct injection or port (i want to know so i can either keep blisten cleaning it which i heard can cause a catastrophe, or get an oil catch can) if some1 can elaborate further. i bought the car when it had 0 km in 2012 september and here we are 7y and a month later with 100k Km ( i live in a dry dusty environment) a lot of stop and go traffic and sometimes long idles on traffic lights). and the first issue i got (mechanically) was rough idle with a little bit of lurching when i creep in traffic (Automatic car). now I have heard different stories about this.
1.issue is with the build up in the engine (blistened flush at least 3 times in 2 different shops)
2.changed spark plugs, cleaned and reprogrammed throttle body with it ( i hope programming was done right as it was simple on YT but some suggested it needed an OBD2 high end device so i went there.
3.something about a common issue w/37 engine regarding catalytic converter producing ceramic dust that damages cylinders sleeve and piston rings!! (my one and first and only car i don't want it destroyed + cannot afford This is mentioned in the websites where they give brief description about engines common issues ( they copy paste each other)
4.I found 1 post saying exhaust cam cover is the cause of the rough idle.
5.Changed the belt (cracked), transmission mount (loose), more than 1 garage said the engine mounts were fine so did not change those (hassle), lastly is coils which i bought but did not replace yet to try to confirm if the other things were the cause.
6. zero codes in both the dealership and indi garage

It was a bit extensive but i had to share it all to make it clear so you guys can have an idea.
so what to do about the engine build up
what to do about these "common" issues and if there are other things to change before they destroy something like a gasket or cooling
and the rough idle issue.

Surfnazi

Change air filters or clean if you have reusable ones.
Clean maf and throttle body
Its port injection you can seafoam it through brake.booster line
Change rad,trans,diff fluid before 100k miles along with spark plugs

3BOSH

thank you so much
i will look through for MAF cleaning video.
however I have no clue about seafoaming brake booster lines (if you can kindly link something)
really appreciated.
are the trans and differential oils have specific grades or only made by Nissan (important since we have so many monopolies and sky high prices per quart of anything)
so do not touch coil packs huh

Surfnazi

Dont change coil packs until you change plugs first to see if it clears up. The vacuum line coming out of master cylinder pull it out and shove it into bottle of seafoam.plug hole in booster with temp plug crank car on rev to 3k rpm till you see white smoke then kill the car and let it sit s long as you have time min 1 hour but longer the better. Plug line back in booster. Turn car on after sitting and drive it like you stole it for 5-10 mins at high rpm and speed. I do it at night or early morning bc anyone behind you wont be able to see and might think you're car is on fire bc white smoke from cleaning carbon deposits will be fog thick. Repeat seafoaming again if needed. But don't seafoam on new plugs butold ones.

stealthee

I remember doing a seafoam treatment one time. I was in the garage and only doing the initial suck up of the liquid before I let it sit. The car started smoking so bad before I killed it that my neighbor came running over because he thought the garage was on fire.

I laughed hysterically, told him everything was good, and thanked him for watching out.