Added RTV to the valve cover nipple and added an O ring to the brake booster upper plenum. No dice...still getting the same two codes. So confused as to what I am over looking

 

Heck block off the nipple on the valve cover & the PCV and see if the codes pop up the same way. If they do you can rule out the PCV. It'll just be like a baffle that is 100% clogged for test purposes.

 

Good idea, I will clamp off the hose at both connections and see what happens tonight

 

Clamped the hose off in one location and got the same P0101 code but, no other codes. Idled a little bit higher but, no other issues.

What is the next thing we can rule out?

 

So P0101 came back but not the P0505? Only difference with your FV308 install is the nipple on the valve cover, but I don’t see how that would alter the flow that much. I mean on the 99-02 OEM nipple it’s 100% wide open & no faults on any of my 3 D2’s. Unless the vacuum leak from the brake booster fitting is enough to offset things.

Do you have another MAF to slap on to rule out the MAF? Also just curious after all this engine work have the adaptive settings been reset? Whenever I replace a MAF, O2 sensors, or do any kind of a tune up I always reset the adaptions.

 

I do not think it is a large enough leak to cause an issue. I am assuming it was leaking before the HG job but, adding the extra O ring yesterday did help with the leak. Oddly enough the P0505 has not came back yet. I need to run the truck a few more miles to see if it comes back.

I have only been deleting the pending and active codes, no adaptive reset since hooking everything up and plugging leaks. I can unhooked the battery to reset the ECU's adaptive settings. I might do that next just to see what happens

Bad MAF...I thought that might be the issue but, why would it suddenly act up after HG job. Also, because I can see the readings on the MAF go up and down with the RPMs I have been ruling it out. In short, I do not have a spare MAF I would need to buy one. However...if someone could run similar test (engine temp, RPMs, and MAF readings) on their truck I could probably get some better direction.

Also to be clear, the engine is running fine except the bumps in the RPMs and codes. Another reason why I am perplexed.

 

I’ll dig around and see if I have a spare MAF laying around.

 

After adaptive reset

No P0101, however P0505 pending came on after holding RPMs to 3.6k for a minute. Idle started to bounce around

When I cleaned the IAC, it was pretty gunked up but, moved freely. After cleaning it was very smooth. Could this be the issue, the IAV? It has zero leaks that I can tell from last go around with vacuum up the intake and soap and water.

Before I try to figure out too much more, I think I need to drive the truck for a while and get some miles before chasing this one.

 

Yeah I’d drive it some more for sure. Seems like we’ve now ruled out the FV308 as well if it was still pinched off when the P0505 came back.

I’ve got like 8 spare Bosch IAC’s in stock and I should have a Bosch MAF sensor as well.

 

after driving another few miles I can check with a meter to know if IAC is bad.

thanks for helping me troubled shoot this