Help needed, miss 2001 4.7

Hello, new to Tundras and the forum

Have a slight problem puzzling me. Truck has a miss when cold. If I let it warm up its fine, even idles great cold but underload (climbing) i get a missfire to the point it bucks. No light and checked, also no codes.
I suspected an O2 sensor, looked to price them and am given choices of O2's and AF (air/fuel)
My questions, the truck has O2s or AFs?
and any ideas on what i could check other than O2s? or think i am on the right track?
Thank you in advance for any and all help, ... Joe

 

As far as I know and remember bad O2’s were never a problem for me like you are having when they went bad. My mechanic said don’t worry to fix right away unless you really want to fix it right away. My check engine light would come on, but I would reset it constantly knowing it was o2.

Another problem I had was similiar to what you describe was fixed by buying a brand new gas cap! Got that fuel reading you described as AF. Bought a new gas cap and that fixed it. Something about the seal. New cap is about $15?

 

Welcome from Texas

 

Hello Lone Star,
Greetings from Pennsylvania

OK got a new cap today, sure hope it's the fix, love this truck.
They are solid built and the trq. these engines make is perfect.

Will update, I thank you both ☺

 

Could be an Ignition coil.

 

Was it the gas cap?

 

OK update, replaced gas cap, no luck
Keep driving and finally got a mil light and code
P0430 Catalyst System Efficiency Below Threshold (Bank #2)
Where do i start with this? is it an O2 or the Cat?
Thanks in advance,

 

O2 would be a cheaper try then the cat....

 

Bank 2 is pass. side behind cat?

 

Yes
I'd replace the O2 behind the cat. Unhook the battery for a few minutes to reset the check engine light.

02 sensor is more likely to go bad then a cat......

 

OK decided I'm going to do Cats and O2's
Considering I wont have a way to a parts or hardware store once I pull this apart
Would anyone know what hardware I will need?
What size nuts/bolts
and from what i can see the rear O2s are stud mounted?
what size nuts there too?
I'm going to go with all stainless steel

Thanks again for all the help,