Transmission Slipping? (intermittent loss of power feeling when flooring it)

@lr172 @ABA180 @Dm93 It might also be relevant that for the past couple of weeks, maybe 2 months or so, the truck has sounded... louder? The engine sound is more prominent then it used to be (I think this isn't just in my head)

I did crawl under the truck to ensure it still had cat converters, it does thankfully so robbery isn't the issue.

Just wanted to add that while I wait for a scanner to arrive in case that helps narrow the potential issue list at all, thanks again guys!

 

That's a possible check mark in the restricted exhaust column but let's see what scan data shows before we start looking that direction too much.

 

This is true, I meant more that it's possible one is clogged. But as @Dm93 said let's scan 'er up

 

@lr172 @ABA180 @Dm93 while waiting on a better Scanguage to arrive, I did have an old cheap $20 one from years ago around. I watched the O2B1S2(V) and 02B2S2(V) as I drove around for a bit. It appeared to idle around .68-.78(V) and be under that when accelerating. I did see it make dramatic drops to (either .125 or .0125) during punching the pedal and peeking at the live data as it did the "bogged down" thing. This picture is from Youtube but if the (V) range I am looking at is correct for whatever O2 sensors are in my truck, it appears to be having a lean issue during the weird feeling? So based on earlier comments from @Dm93 we are leaning towards fuel/MAF issues and not a plugged cat?

I am using:

$27 ANCEL AD310 Classic Enhanced Universal OBD II Scanner Car Engine Fault Code Reader CAN Diagnostic Scan Tool, Read and Clear Error Codes for 1996 or Newer OBD2 Protocol Vehicle (Black)

This Scanner

This scanner has TP(%) and MAF(lbs/min) What would I be looking for with the MAF and TP during the bogging condition?

 

I sprayed out the MAF with a MAF cleaner and don't really feel a difference, just an update

 

I'd want to watch AFR (upstream) sensor readings more than downstream but it seems you may have a lean condition.

APP and TPS should increase linearly with pedal movement with no dropouts.

MAF g/s at a hot idle should be aprox equal to engine displacement in Liters which would be 4 g/s for the 4.0L.

To test MAF accuracy and overall ability of the engine to breathe you would need to do what we call a VE test, this would be a WOT pull through 1st gear while recording IAT, peak MAF, and Peak RPM then drop them in the calculator below.

https://otctools.com/ve

 

You need to be observing the S1 sensors, as these are the ones that respond to what is coming out of the cylinder. The S2 are after the cat and have been converted (remember it is a catalytic CONVERTER. It change the composition of the molecules by stripping and combining, creating new molecules)the only value of the s2 data is to determine cat effectiveness. You need to post the maf and tp data, along with the O2s1 data, both relative to rpm. Then we can help to see if they are tracking correctly.

first lets get a confirmation that it is going lean at WOT, which i suspect it is. Then we need to determine why it is only lean during the rapid throttle movement phase and then richening up once things stabilize. Engine need X cc’sof fuel @2000 rpm in a steady state. But if you punch the throttle to move to higher rpm, the engine needs at least X cc’s plus 10-20% fuel @2000 rpm to handle that transition and you get the bog if tht extra fuel is not added.

ecu determines that you went wot by observing the speed and range of movement of the throttle, hence why we need to see tp data.

 

Apologies for the delay, but the issue ended up being either the fuel pump or filter (internal part of the pump) so a swap of the pump fixed the issue. It no longer bogs down when 3/4 throttle. I had a friend diagnose it in a shop and the fuel pressure was way below what it was supposed to be delivering