Taco has a hesitation!

Not always. In my case, it wasn't until the o2 actually crapped out that the CEL came on and in my buddy's case, he had no CEl at all but had very similar experiences as the OP and myself.

To OP: Check your tailpipe and see if the inside is blacker than normal. A faulty o2 will result in unburned fuel going through the exhaust thus leaving soot in the tailpipe. Even if it isn't the actualy issue, at his mileage it is a good idea to swap out.

 

Well I am at wits end , Update: New oem Denso plugs gapped to .42, new fuel filter, new plug wires, new throttle position sensor, new afe dry filter, new pcv valve, new front CO2 sensor, new battery, throttle body cleaned, Mass air sensor cleaned, 1/4 can of sea foam in vacum system, 3/4 can sea foam in tank, The truck seems to run fine but it will give a hickup when the throttle is chopped and re-aplied, like it hesitates on the kickdown shift? Sometimes when you get on it it kicksdown but hickups at the kickdown. The idle seems a little ruff as well. The only thing left to replace is the back CO2 sensor, and the Mass air flow sensor. The engine light has never come on. I tried the propane torch unlit trick to try and find a vacum leak but found nothing! WTF!!!!!

 

when you get back on the throttle, or give it juice. Are you doing it kinda quick? (giving it alot).
Bc I know that the automatics will hesitate for a sec. before downshifting or kicking down. its just how they are.

 

Not quick, maybe 1/4 throttle? It like stumbles/hickups when you let off the gas then re-apply the gas. Does the mass air sensor throw a code if its going bad?

 

Huh.... It should, but I know that sometimes it wont. Just like a bad o2. you could have the symtoms of a bad MAF or a bad o2 and no CEL. you know...

But from reading it sure does sound like its a bad MAF sensor. sorry man!
I know those things are spendy little bastards.

 

try doing the deckplate mod. my dads 3.4 hesitated, then we did the deckplate and added on a flowmaster muffler and it went away.

 

I just pulled off the intake hose and used a crest electric tooth brush to clean the throttle body, should I remove the throttle body and do it again? Is that IAC the thing right under the TB? How do you clean the IAC? Did the deck plate mod awhile ago, no help.

 

Thanks, will do it this weekend