So, im guessing that it's the second one? (feelin a lil slow today..lol)

 

Check fuel pressure when you first turn the key. See how long it takes to build to 49 PSI while cranking.

Being able to see what various sensors are telling the PCM at cold start would be nice.... but, I have noticed very few folks have the capability to do that....

 

I go to start my truck..it turns over and sputters out. The Cat was replaced a few months back, and I thought that it was the issue. Battery isn't that old (red top), and the starter is fine. I haven't checked the plugs...but I don't think it would be them.

The same thing happened last year when it started getting cold.

 

hmm...so, back to the original question. I know that the sensors are mostly stock...and original...worth trying the cheap option first. Which one do I need to get? I don't have a fuel pressure tester off hand.

 

A fuel pressure tester is like $25, an IAC is 40 to 100 depending on where you buy it. Get a Haynes manual at least also.

 

Already have a service manual and a Haynes...i'm just trying to figure out what they were meaning by intake air temp sensor...

 

That sensor is on the pass. side of the intake manifold, and it's not the problem. The first thing you should do, since you are new here, is do a search for plenum on DF. Eliminate that common problem from the equation and go from there. I for one, will be more than happy to help you with any questions after that.

 

I'm not new here...and I wasn't aware that the plenum could be it, but...I will research further.

 

the plenum don't sound like your problem like everyone else has said the prob. your iac (idle air contorl) motor my 5.2 on the throttle body in back. it maybe different on the 5.9's. try this cheap fix to see if that it take brake cleaner and carb. cleaner to the iac motor and clean it if you stick it back in and in the morning when its cold it runs good then you need to start looking for one or you just clean it once or twice a week like that. i do that all the time mine 10 dollars every few months isn't bad to clean it. the park at advance is 150 dollars on the 5.2
good luck

 

I didn't say the plenum "could be it" I simply said , it needs to be eliminated and taken out of the trouble shooting equation.