Engine occasionally stumbles

[RegularGuy]

2007 sohc fx4
The truck lacked of power up until I replaced the battery on the 2nd (related? Idk). Now the power is great but after about 20 minutes when the engine warms up, the engine appears to momentarily die before it catches itself. One, maybe two cylinders in a row spaced out 10-30 seconds, sometimes up to three times back to back....
The engine does exactly the same thing at idle so I doubt it's fuel related. When driving down the highway, it feels like someone has momentarily engaged trailer brakes. The truck suddenly slows down a little then the power comes back

The engine does the same thing regardless of electrical load, lights, stereo, fan

A list of things which come to mind:
My A/C is likely low on the cool stuff
Spark plugs, wires, and coil are of an unknown age... They could potentially be cracked
The power cable for the subwoofer is run against the harness coming through the firewall below the steering wheel (same issue with stereo off though)

Where should I start for the sake of time/money saving purposes? Check engine light isn't on, if it was my first guess would be a misfire code

 

[RonD]

Clean the MAF sensor, once a year

And put a can of Seafoam or similar injector cleaner in the gas tank also once a year

How many miles on the O2 sensors?
They need to be changed every 125k miles or so, will improve MPG over the next 125k miles so they pay for themselves

 

[Dirtman]

Temporary bogs like that can be related to a leak in the evap purge line or solenoid (when the evap system purges you would get a massive temporary vacuum leak) BUT there should be an accompanying check engine light for that.

The bulbs on the check engine light do burn out... does the light come on when you turn the key to the run position?

 

[RegularGuy]

The truck does what I can best describe as 'hicup'. Dash lights all work, I would believe a sensor issue to be a more regular occurrence than a fraction of a second twice a minute... I'll see if I can't get it on video. Although its a pain, I'm going to try pulling the spark plugs tonight for potentially fouled plugs

 

[RegularGuy]

Prior to the first post, I checked the airbox to find minimal contamination.

As of yesterday:
Cleaned the MAF (that spray wasn't cheap!) which has helped a small amount although the problem still persists. Pulled the plugs and they should have a couple miles left on them, none of them were fouled or burned.

I pulled the coil pack, gave it a good washing, and checked it for cracks. Tried following a how-to testing it with an ohm meter but was unable to figure out how to do so

Currently, my next logical step would be to put some injector cleaner in the truck... While it doesn't make much sense to me, the MAF made a difference so maybe the injectors will too. The truck currently has 119k, o2 look new though so they should be alright

Never did get the problem on video, when idling, the tach dips about 100-200 rpm before immediately coming back up, similar on the highway too

 

[Dirtman]

Get the seafoam 2 pack. One is the can that you pour in the gas tank, one is a spray bottle that you spray through your intake tube.

Its not a miracle cure but the stuff does work. I do a bottle in the tank every oil change and the spray intake once a year. Pulled my intake and fuel injectors last week and my intake valves looked like new and fuel injectors were spotless. So its more than maintenance than a cure but its worth a shot.

I still think theres an underlying issue, leak, sensor on the fritz ect.

 

[RegularGuy]

Truck is fixed!

Tonight I blasted the throttle plate with cleaner, added 12oz of r134a to the ac system, and pulled one sparkplug, wire brushed it, then returned it to the engine.

Of everything I did, I'd have to say it was probably the AC which was causing my issue, otherwise I either got lucky by pulling the one wire with a faulty connection or, the little bit of grime on the throttle plate really did make a ton of difference