If you put a new ECM on and then also put a new IACV in, does it need to be re-programed with the new ECM? Thats the next thing thats being done tomorrow to see if it fixes my idle & stalling while in park problem. Anyone??

Honestly, I'm not sure. I've never encountered an issue like yours before. These modern ECUs do "learn" a lot of things and can adapt and change over time to adjust to your driving habits, but I don't know if IACV is included in those learnable parameters or not. Sorry.

I am also not sure.

Well they say its the Air flow sensor, which is the Mass air flow sensor. They claim its bad and they put a new one on & it made a big difference in the shifting, accellerating, and stalling & bad idleing while in park. I told them to make sure it was reved up while in park cause thats when it usually died out. He claims he did that and it never died out again. Wants to keep it overnight & drive & idle it off and on to make sure it truly fixed it. I told them the other day to check the mass air flow & they said they supposedly did & it was ok, but today they must have! Seems like they did not want me telling them. I asked them if a sensor can be malfunctioning and not working right, but not set off the CEL & he said no. But if this Mass air flow was no good, then why was it not causeing the CEL to come on? Unreal how they answer you. Now I go to the forum below in the link & this is a very common problem that I'm going thru with certain year Maximas. They say a K & N air filter can cause the MAF sensor to go out cause of the oil on the filter, this true? Also they say when you replace tha Mass air u should put new air filter in at same time and get computer reset? Alot of others say they just disconnect negative battery cable for 2 hours then the computer will reset itself to the new mass air, true?. Here is that link below with a ton of other peoples identical problems with CEL coming on & replaceing all the things that I have to correct it.

http://www.carsurvey.org/revie...age-2/

I think the tech may have misunderstood your CEL question. Either way his answer was incorrect. The MAF (air flow sensor) will NOT cause the CEL to illuminate if it is bad.

It does make sense that the MAF would fix the issue. The car uses MAF data to decide air/fuel ratios, so bad MAF data could easily cause the symptoms you've been seeing.

You shouldn't need to reset the computer, but it certainly won't hurt. I would only bother with a new air filter if yours is in need of replacement.

What about the K&N oil filter causeing MAF to act up & go bad? Some are saying on that link in my prior post that the oil from the filter messes up the MAF as it attatches to it. And it really makes sense the more I read on that other forum with soo many others having the same problems like I am having on their Maximas,Sentras and other Nissan cars, I felt that my gas mileage has been horrible and they say a bad MAF can cause poor mileage and shifting that is not smooth which also I noticed on car. Seems to be pretty wide spread on them & alot of them say after replacing so many different parts, each time they do, a month or so later or sooner, CEL keeps coming back on. Some say its very intermittent and feel maybe a spike from the alternator is throwing false codes to come up, and thats why when they take it to get looked at, nothing shows up.

if you put a new ECU in, of course you need to reprogram it. The idle re-learn has to be done at the dealership, it's not something the car does by itself. And you put a new ECU in because your IACV was broken, not the otherway around. It has nothing to do with the air filter. It's a thing that wears out after 100k or so. Maximas are prone for it. When the IACV goes out, it fries the ECU.Next step re-learn and it should work for another 100k.

Well McSteve, I think u misunderstood what I wrote. Of course I know you have to reprogram the new computer. And yes, I put in a new ECU because the IACV fried it and not the other way around. I knew that. You say " It has nothing to do with the air filter". What I was refering to was that I have read on other boards that useing a K&N air filter can be the culprit of a MAF going out because of the oil you apply on the filter gets sucked in and on the MAF causing premature failure. And I was asking if anyone could confirm this. I was not claming the air filter caused the other problems. And please, dont take this the wrong way, I'm not talking mess to you, I'm just trying to explain to you what I had meant in my prior post. This has been very frustrating dealing with this problem & a shop that dont seem up to par on this problem.

I told them it had to be taken to dealer to idle relearn & they said it did not, Next day they tell me,"Oh, we gotta take to dealer to relearn it" I was like duuuhhh I told you. LOL. Well I sure hope when I pick it up tomorrow it is fixed like they swear it is. After spending $1,900 for all the new parts & tranny fluid flushed I'm not in the mood for any lies. I'll let you all know.