So here it is...
loud popping through the power band has the title states.

It pops/hesitates at idle
It pops/hesitates under light/heavy load

So I'd be at a traffic light idling, the rpm will slowly go below the regular threshold and will start idling around 200-300rpm hesitating and popping.
As I start moving forward it starts hesitating/popping even more, it feels like the car is going to die, but it accelerates and keeps popping/hesitating
Every once in a while it feels and sounds normal, but starts popping again as I start playing with the throttle.

If I downshift and let the car coast, there is no popping what so ever.
It only happens when standing still(at idle), or when I accelerate or when I try to maintain my speed.

No CEL.
2nd cat converter is brand spanking new
1st cat converter was hollowed out yesterday(just in case it was clogged)
I ran countless cans of seafoam through the intake manifold and the gas tank
Spark plugs seem to show normal wear and tear, although maybe a bit on the hot side of the spectrum.

Only "mod" on the car is a short ram intake and a fart can. The filter on the sri is clean and breaths alright.
The maf was cleaned a few days ago and it hasn't change the issue. If I disconnect the maf while the car is idling, the idle will change but the problem remains so I'm ruling out the maf as being the possible cause of this.

Weird sounds and problems like the one I'm experiencing are really hard to describe over a copper wire
Hopefully I can record the sound on my way home tonight.

It's been happening for months, so it ain't just a bad batch of gas.



And eh... why would I loose 12840 Experience points?
05:20 PM blaze_125 has lost -12840 Experience points

 

Have you changed the plugs in awhile? Just because they "look" good doesnt mean they are. Sounds like misfiring to me. If it was me I would do a comp. test and change the plugs or at the least re gap them. Maybe timing belt jumped a tooth?

 

When I first started troubleshooting this, I did change the plug and it had no impact at all.
There is little mileage on my current plugs, but I guess sometimes the obvious is just too obvious. I'll change them again. But keep the suggestions coming.

As for the timing belt jumping a tooth, I'm not sure how I'd find out if it did.
I thought about it for a while, and it doesn't make sense to me. I'm not familiar with belt issues so I might be wrong, but I'd think that if the belt jumped a tooth, the problem would always be there no matter what I do with the throttle.

I recorded a few clips on my way home, but it's too hard to notice the popping to even bother uploading the clips...

 

Yes it should be there all the time with a timing jump but stranger things have happened. Comp test would tell you if timing jumped as comp would be lower.

 

Turns out, years of P0421 shortens the life of the Check Engine Light.
After everything I had done so far such as unplugging wires, the CEL should have been ON and it wasn't so I connected the code reader anyway.

4th cylinder misfire

Which one is the forth cylinder? Far left, or far right?
I still changed all the plugs anyway. Properly gapped.
The problem isn't as noticeable but it's still there. So something is definitely happening in that combustion chamber.

 

#4 is closest to the drivers side. If problem is still there but lessened then could be weak spark from bad coil pack. Low compression in that one cylinder. Or clogged fuel injector.

 

I'm'a do a compression test over the weekend.
We'll see what that leads to...