Codes P0171, P0174, P0430, P0300

Yeah it is an old timers trick. The only things that I am not grasping is what the best vacuum line is to take off to test it and what do I do with the component of the vacuum line that I pulled off? I mean do I have to put a t in it with a hose so everything stays connected or do I just block the whole of the component that I took the vacuum tube off of? I do not see any direct vacuum lines going to the upper intake manifold. What about the PCV tube?

Okay, so leave the PCV valve in there and just use its hose that goes to the elbow behind the TB. Would I need to cover the top of the PCV valve with something while doing this?

Haha, well I am glad you learned something from me lol. So this done with the vehicle turned off I assume?

Yep. LOL

Okay. So I smoked a fat cigar in less than five minutes and not only did I manage to find a couple of air leaks, but I also smell like an old man with good luck at a poker table. LOL. I can vouch for the cigar test but only if you use at least a 3/8 hose, because you cannot push enough through a small 1/4 line if you are trying to test everything. Plus it will give you lockjaw's (which is another problem you do not want).I went through the PCV tube on bank 1 (passenger side). The first leak was found off of the cold air intake. I have two outlets about half way down the intake pipe. The bottom outlet goes to the PCV valve on bank 2. The outlet above it goes to the IAC valve in the back(its against the back firewall right above the notorious boot that dry rots.) Both leaks was on that line. Someone who had the truck before me used a piece of hose as a sleeve between the hose off the intake (1/2 in) to the hose going to the IAC (5/8in). It was not tight so unmetered air can get in. The other leak was actually at the IAC valve. I put this part on about 2 months ago because of this vacuum problem. The smoke was coming out of the bottom of a little metal cap that has made on to it. I believe this metal cap is meant to be designed this way for some reason but when I put a little carburetor cleaner to it while it's running, there is no difference in idle.

I fixed the hose problem and I am not sure if anything needs to he done about the IAC.

This is not my IAC but its the same one for my truck and here is the cap I am talking about. It seems like it is for venting because the cigar smoke came out from under it. It was not excessive smoke but a small amount.

So after further research, I have read that this cap is suppose to do that. It is unmetered air but the PCM compensates for it. The cap is for pressure relief to balance the idle speed and without it, the idle cant be stabilized. That is good to know.

Well I smoked the cigars but I did not inhale, LOL. I did it again after I repaired it and it worked. The only thing is, I will know more when I crank it in the morning because it idles and runs badly until I drive a few miles. I think the intake manifold gasket is messed up and when the motor gets warm, the gasket seals itself again. I will report back tomorrow with details but I do not expect this issue to be the only one.

So I fired her up this morning and there is still some tough idling going on but it does not seem to be as bad. I will say it has improved by 25% so that hose was a problem. I have sprayed carburetor cleaner all around the intake and never got any changes it in idle. It is so weird but I am never going to give up on this piece of crap because it gives me something to do, lol.

I wonder, what are the odds of the cold rough idle being a ETC sensor?

Can air getting into a small leak hole in the exhaust cause this problem? I like said before, there no driveability problems and no idle problems after the motor is good and warm. Just idle on the first start up of the day or after its sit for about nineteen hours or more.

Right! LOL. I knew it would not necessarily throw a code. I do not have a live reader yet but I will have one by Christmas LOL. I will know a lot more from that probably. I do have a cheap scanner and it shows freeze frame and PIDs but it is not live. I wrote down all of the information from one of the codes. It will not show me the advanced info of multiple codes, just the first one. Here it is:

This was before I fixed the hose yesterday.

P0174
CL
Etc 176
Shrtft1 16.4
Longft1 25.0
Shrtft2 8.6
Longft1 25.0
rpm 1430
Vss 40

What does this mean, a bad PCM? What can cause that?