2000 Ford E150 4.2L, 165,000 miles

Hello all, I know this is probably the millionth post about this issue but I'm really frustrated.

I purchased this van a few weeks back and it ran fine and all of the sudden...

At first I was getting some slight hesitation under light acceleration, it went away once I gave it gas. Service Engine light was coming on and took it to Autozone, called for new upstream O2 sensors. Not being familiar with the van, I changed the two downstream sensors and then ended up changing the two upstream. Code goes away but the hesitation does not.

So...I decided in my infinite wisdom to do some research hoping for a quick fix and initially replaced PCV valve and grommet, cleaned checked for any rotted vacuum lines and bad plug wires/plugs. I also cleaned a pretty gummed up throttle body.

A few days after I'm driving along and the van starts to run rough and shuttering hard between 30-45 MPH under light acceleration. Foot off the gas, problem goes away. Service Engine Light back on and new blinking. Take it back to autozone scanner can't find vehicle. So I decide to run to Harbor Freight and buy a OBD scanner. New scanner gives me a few different codes: PA113, PA102, PO113, PO102. I research codes and after all end up replacing Mass Airflow Sensor but to no avail. Now, PO113 and PA113 are for the intake air temp sensor which I believe in this van is inclusive of the Mass Sensor as I couldn't find it. I also checked the vacuum from the brake booster line and it all checked out.

Still no fix. So, decided to check plugs again and even changed wires. Still not fixed.

I've read plethora of posts/threads that leads me to believe I'm not even close to figuring out the issue. Some people point to fuel injectors, others claim a plugged up CAT while others say to run some Sea Foam through the system.

I'm just not getting the part how the van ran fine up to one point and then all of the sudden...

Any replies will be greatly appreciated.

 

Update:
After further research, I found that the coil pack was bad.
Not the smartest way to test but...
I essentially started the van, one by one lifted each plug wires from its respective orifice, and the one that didn't arc was the troubled port/cylinder.
Knowing that the plug wires were good (new) and same with the plug, it was safe to assume that the coil pack was bad. Another $82.00 for a coil pack at Autozone.
Van runs flawlessly with one exception... the IAC valve is now acting up, I assume it has something to do with the cleaning i did of the throttle body. Will take it off today and give a healthy cleaning with some throttle body cleaner.
I have also put some Sea Foam in the gas tank in the hopes things like fuel injectors will get a good cleaning as well.
Hope this helps someone in the future.

 

Thanks for the update