Few weeks back I decided to keep my AP1 and fix it instead of trading it in for an PA2:
https://www.s2ki.com/forums/index.php?showtopic=813137

Few days after that the car developed another problem. It started to stall at stop signs and there is also some bucking/jerking when driving both at steady speeds and during slight acceleration (between 3-5K RPM).

I had the stalling problem before and it went away with the map whack/cleaning so I tried it again but it made no difference. So, I replaced the MAP sensor with the new one including the zip tie but it made no difference.

In the mean time I had already ordered a new PCV valve and inline pro TCT so I replaced them as well - this did not make any difference. I will have to drive the car a bit more to see if the new TCT has fixed that card in spokes sound.

Next I ran a compression test (my first time ever trying it but it was pretty easy) and the results were 240 all across.

I noticed that the spark plugs were not in a good shape (car's at ~ 80K miles), the gap way way over spec. So, I changed them as well.

After all of this and reset of the ECU, I still have the same problem with stalling and bucking.

While changing the TCT I noticed that the air filter was dirty so I will replace it next but somehow I find it hard to believe it would cause this problem.

The reason I'm scared is that during my search on this issue I came across some threads where people had similar issues and their car ended up dying - most of those problems had to do with crank walk on modded cars, mine is completely stock.

Is there any way to check for crank walk without running the car? Now I'm really scared to even start it and have been driving the Explorer lately.

I would appreciate any advice.

 

Few things came to mind real fast for me:

If your filter is REALLY dirty, maybe not enough air is getting through it.

With the colder weather, the ECU is re-learning the curves (also doesn't the fuel formulation change this time of year?) so maybe it needs some time to re-learn fully. resetting the ECU may have contributed to that.

Maybe the MAP sensor is bad. Try the whack?

 

what type of clutch do you have as crank walk seems to be tied to certain clutches

 

HARDtoTOP: I will change the filter tomorrow, I'm just nervous to drive the car now. This is not the normal weather change / ECU learning issue, I'm pretty sure about this after all these years. Also, I've already tried the MAP whack and even changed it with the new one that comes with a zip tie.

josserman: Stock clutch.

 

Ive seen crankwalk with stock clutches ....two to be exact . Not saying youre problem is crankwalk . With crankwalk the clutch pedal will not be consistent as to where it grabs . So if youre clutch feels weird then you can start to worry otherwise youre ok . Other things to check would be the primary o2 sensor it could be getting sluggish or the iac valve could be dirty and or need to be replaced and lets not forget about the tps . You need someone who knows what they are doing to check the car over instead of replacing good parts for no reason . It will get expensive fast . Honestly i doubt the problem is serious as the s2ks are good cars .