2003 XLT 4.0 died at stoplight

[Wilderness1996]

I have a 2003 ford explorer 4.0 SOHC 220K miles, I have done alot of maintenance on this vehicle over the years, but yesterday the engine began to stall in traffic, it shook, I pushed on the gas and it was sluggish going forward, I stopped again, tried to push on the accelerator and I believe the engine revved but received no response from the wheels.
I so far I believe the fuel pump is working as my front fuel injector O ring is still leaking under the rail when I turn the key to the on position. the starter turns the engine over but it doesn't sound like I am getting any effort of the engine starting. I have already tried swapping out the coil pack incase that was the issue. There are currently no codes on the dash besides check gauge and service engine soon which has always been on.
when it turns over it doesn't sound like anything is hitting or scraping, when it died it didn't sound like anything rough happened.
The timing chains, head gaskets, valve lifters, alternator, waterpump, sparkplugs, wires, have all been replaced within 20k miles.
Does anyone have any ideas? After typing this up I will be checking the spark plug wires for resistance and check each spark plug for fouling, but maybe its a clogged catalytic converter or my fuel pressure is low from a clogged fuel filter?

 

[J_C]

So it was running acceptable before it suddenly stalled in traffic? If so then I doubt it's a clogged cat, would tend to have built up to where it is now over time, with more evidence at higher engine load before dying at idle.

Letting some problem persist where the dash lights are always on can be problematic because they then don't serve the purpose they were intended to. Do you know what prior problems or codes where set to cause that so we can either ignore them or focus on them potentially getting worse?

If you have leaking injector o-rings that is certainly something to look at fixing now, besides DIY labor that is an inexpensive repair.

Ultimately I'd want to pull the OBD2 codes at least then if nothing looks conspicuous, do a fuel rail pressure check. You could also try starter fluid to see if the engine will start. While you have the plugs out, if you have a helper to crank the engine then you can check for spark holding the plug threads to a chassis ground.

I'd also keep an eye on the battery voltage. Since it still seems to crank it "probably" isn't low but there is a threshold where it could still crank in warm weather but not generate consistent spark, plus continuing to troubleshoot, I'd want a battery charger on it to keep it topped off till this is sorted out, and initially charging it up then trying to start is an easy check to do.

I wouldn't bother checking the spark plug wires for resistance, I mean you might have one that's bad or misrouted and damaged by exhaust heat but that shouldn't suddenly cause this failure to even start, would tend to be a single wire at a time that failed then loss of two cylinders (waste spark system so one wire affects two cylinders' firing), should still be able to start or at least make a noble effort and sound like it's firing on some cylinders attempting to start, but if none are firing then possibly the ignition module or low battery.

I'm getting ahead of myself, check the OBD2 codes and ideally if you can coax it to run, look at the long term fuel trims if the scan tool supports live data.

 

[Josh P]

Are the timing chains original?

 

[J_C]

The timing chains, head gaskets, valve lifters, alternator, waterpump, sparkplugs, wires, have all been replaced within 20k miles.

 

[Josh P]

I misread the within part