I recently posted a thread about bad fuel consumption after cleaning my tb and iacv. As previously stated, I had to replace my maf after cleaning the tb and iacv and have been getting bad gas mileage ever since. The car was running perfectly fine except for the fuel consumption. Today, I decided to take the car to the dealer to have the ecu reprogrammed. I found out that after they diagnosed the initial situation, bank 1 was running at 87% and bank 2 was running at 89%. I'm not quite sure what these numbers mean, but if I understand correctly, this represents the air/fuel mixture ratio. I was told that these percentages were low and indicated that the system was running rich. I have only driven 10 miles since then, so I haven't been able to tell if the gas mileage has improved. Surely, since the car was running rich, my gas mileage will improve. I will post updates once the car has been driven more. Oh, btw, I was charged $83 for those that are interested. I would recommend doing this after changing your maf if you haven't done so already. Hope this helps.

 

after changing the MAF and driven for a few miles the ECU will reset itself for the new one....

 

So...how do you explain how banks 1 and 2 were running rich. The tech showed me the printout of the before and after readings. I don't think it was running rich before the maf. I haven't seen anything put out by Nissan that states that the ecu will correct itself after the install. Either way, I was just posting my findings for those who may have experienced the same thing I have, in case it may be of some interest.

 

I replaced my MAF just for the heck of it and the car runs normal w/o the ecu reprogram... don't know but someone here with more knowledge than me can explain the whole thing

 

My max ran normal also after installing the new maf, but with the exception of poor fuel economy. No high/low idle or anything. I don't have much knowledge either, that is why I took it to the dealer. Hopefully, since the car was running rich, the gas mileage will improve back to the way it was before the new maf.

 

just fyi, to make the point of the difference between resetting the ecu and flashing the ecu for the maf update that was part of the tsb. i replaced my maf with the updated part w/o the flash update and had no issue. my 2nd to most recent dyno indicated i was running very rich at wot as well but mine was most likely due to the headers or perhaps a combination of the two.

 

could a SAFC fix the a/f ratio?

 

I am a newbie, so I have no clue what a safc is or what it does. Sorry...I can't be of much help to you.

 

safc's should be able to correct it

 

yes it will but i would advise to get a vafc2 instead. that is what i currently run to keep my a/f optimal.