Start up rough idle

When I start my truck in the morning it idles well at about 950 rpm. After it starts to?warm up and is starting to idle at a lower rpm it starts missing. I took the air intake tube off to expose the throttle body and cleaned it with some cleaner and a clean rag. The engine runs fine and it doesn't seem like there is any power loss. My mechanic is talking about a throttle body replacement but I'm not understanding his thinking when the engine runs fine. I know there are other components mounted to it. Can I save money by replacing any of them? Idle air control valve for instance? Also, would a bad spark plug cause rough idle but work fine after it warms up? I'm sorry fellas I'm desperate. Don't want to spend hundreds of dollars that I don't have. Someone please help.

 

Fouled spark plug(s) could cause your issue, when was the last time they were replaced?

Try cleaning the MAF sensor

 

New plugs, air filter, clean MAF and see where you are at after that.

 

Ok latest update. Plugs are clean and gapped. Coils are good. MAF sensor cleaned. Throttle body cleaned. The only issue I have is first start up of the day. It won't idle smoothly. I do the procedure that resets the idle in the computer. Then it runs fine. No starting problems the rest of the day. Idles fine. No power loss. What could it be? Is that something I'm missing?

 

Hmm did you check your fuel pressure? Also watch your MAF and see if it's working alright during idle. You'll probably have to baseline it with another similar setup Tundra and watch the graph on starting to compare.

Also could it be that there are manifold gaps that get plugged up when the engine gets hot. Allowing you to take in extra/unknown air during start up but not when the gaps are plugged when hot.

I would baseline the manifold stuff with looking at some short term/long term fuel trims. With a good working Tundra.