Is it possible to have a bad IAC valve ( Idle Air Control ) and not have a code to come up ?

 

yep. you'd have problems keeping the truck on. Two-footed driving would solve a problem with the IAC.

 

Could be sticking or not closing properly, but still allow the engine to run. It would not run well, but it would run. What are your symptoms?

 

Rough idle, two footed driving at times, going dead at red lights. I was asking the question because while this is going on, I am not throwing a code in the computer. my scanner gives me no faults. this part cost me $ 80.00 and I did not want to put it on if not the problem. any advice would be great. thanks

 

Clean it. Remove the throttle body and give the whole thing a good thorough cleaning.

 

advice please, on what would be a good product to clean it with. I want to do this right the first time. also do I need to note were the pintle is, so to make sure it goes back correct ?

 

Any sensor safe carbon cleaner will work nicely.

Also, you should disconnect the battery so that it goes through the IAC position relearn the next time you start it up.

 

what about the pintle position, do I need to make sure it goes back in the same way I took it out ? also can you get a new o ring with out buying the whole part.....thanks

 

You should not need to replace the o-ring. And just make sure that the connector is in the same orientation. That is it. If you do not move the pintle, you should not need to disconnect the battery. It will relearn idle ok if it is a marginal change from the original position.