So I recently just got my T4R back on the road... kinda. I did a 5 speed swap with my parts car that I picked up in Arizona (federal emissions). I live in California which has its own emissions, because my truck is CA i needed to swap the wiring harness with the secondary o2 sensor. i had all this buttoned up with a Napa ECU. When i "finished" the project it was of course time for a test drive, with this came a problem with the engine bogging down; checked for vacuum leaks, replaced fuel filter, checked the knock sensor, I checked any connections and still nothing!!! So I thought the ECU I bought might not be working so i tried out the original computer that was hooked up to this harness (federal emissions) and the thing ran a lot better it wasn't bogging down but when under load the engine was jerking almost similar to a misfire? its a good engine it ran perfect before I did the swap I don't know what that is? Anyone have any similar problems before?????

Also I ordered a new ECU from Napa since this one they sent seemed to be part of my problem.

 

Did you check for any stored codes?

 

I am getting no codes. it's running fine on any flats or downhilll but anything that has a slight incline it jerks and has no torque. i switched the coil out and did the same. When i do the jump to check for any codes all I get is the CEL flashing. this thing is baffling me, so I called my mechanic just to get his opinion and he is at a lost too, doesn't even know where to start.

 

Update:
Have some spare parts so decided to replace the knock sensor and the fuel pressure regulator off a hunch, it worked! ...
or so I thought the issue came back once my truck got warm, once it got to operating temp then around 3,000-3,500 RPM I lost power. SO my thoughts are it HAS to be something that is supposed to work fully when warm??? Or maybe the EGR? I'll have to look over the next few days when I get a chance. Fingers crossed!

 

Well i went through all my vacuums and made sure they are perfect to fsm. I checked my EGR and replaced the EGR vacuum modulator. i thought it could have been the CAT and maybe it was clogged to i knocked the insides out since i needed a new one anyways (i.e. bad converter: cat converter made a rattle before the swap) still same problem. It idles fine, revs will climb in all gears when cold, but as I stated before once it gets to normal temp the revs in any gear except first will not go past 3,000. Although after checking vacuum lines today it will bog down until i shift down the they will very very slowly creep up but never past 3,000. Back to square one; not having any leads and I can't just throw parts at it. I really am stumped and have no idea where to start! Any ideas?!

 

EGR vacuum line was cracked! replaced and was running line since.New problem arose because of mess up..? at a loss need any suggestions.
https://www.yotatech.com/forums/f116.../#post52372518

 

Lot going on here.
I ask this question alot because it relates to other people's problems also.
Have you checked your TPS to see if its within spec?