As some of you know I was having hard shifts and low idle for a while. I went to the dealers to have them look at my car and determine what was wrong with it. They did a diagnostic check found no codes, and said it was running good. I beg to differ. They said that its most likely the Mass Airflow Sensor that gone. So they also advised me to bring my stock airbox with me so they could put it on with the new MAF. I wasnt gonna let them charge me to put the airbox back on so i did it myself. Anyways i take the car out for a test drive and i could not believe that the problem had pretty much disappeared. I still get a slight slight hard shift but nothing to the effect it was before. So it gives me assurance that the problem is definitely the MAF. My question is they want 831 dollars to put the new MAF in and then do an ECM reprogram. Thing is i dont know why they need to reprogram the ecm. If i can save myself some money and just buy the MAF and do it myself i would be much better off. If i dont get the reprogram what will happen?

 

imho, replacing a MAF does not require any ECU reprogramming.
not a long ago i've been running some tests on my car, i switched between
2 mafs that i had at least 2 or 3 times, didn't do anything with the ecu, didn't see any difference.

 

thats good to hear. What does an ecm reprogram do?

 

Reset's your ECU so that your car can learn your driving style/what conditions it runs in all over again.

Your car does it automatically, why pay someone to do it for you.

It took my car a couple hours to learn how to cope with boost.

 

i had to have an ECu reprogram back when my car was under warranty and I didn't replace the MAF. The dealer just said that i needed it and they did it. It was an updated program for the car and had nothing to do with anything else getting fixed.

 

Don't they put in a new air/fuel mixture table to match the new MAF when the reprogram the ECU?

 

I agree, you don't need to pay the dealer to replace the MAF and re-program the ECU. The replacement is pretty simple, and the ECU seems to figure it out for itself just fine.

 

If this 'reprogramming' is just resetting the ECU, then you can definitely do it yourself. There is instructions in the stickies. All you need is a stopwatch and some patience. I do this about twice a year, and everytime I do it, my car runs noticeably smoother right after.

 

reprogram is not the same as "reset" or "relearn"

 

I believe reprogramming deals with specific parameters that help with both gas mileage and performance. If you don't get it programmed VIA ecm consult II, you won't get the full benefits of the new MAF...

 

just buy a new MAF and install it yourself and it will reprogam itself

 

it will RELEARN

reprogram is not the same as "reset" or "relearn"

 

Then i might as well have it reprogramed if i will see better gas mileage and performance.

 

I just wanted to comment on the MAF shenanigans. My 2000 SE has been running like crap for two weeks now, I cleaned the MAF this weekend, used some CRC MAF Cleaner, it helped but didn't fix the poor performance issue. So I bought a new MAF off DriveWire, came the next day, with UPS Ground shipping.

I installed it last night, car runs great, but I did not have the ECM reprogrammed.

I think I may go in and have it done, I have never taken this car to the Stealership for anything, but I guess this I will have to give in and do it.

I hear a lot about the K&N filters being the cause of this, I think that is just Nissan trying to scapegoat someone else for their poor quality.

I don't have the K&N filter, I have a JWT PopCharger, but I use the K&N filter oil on it. I have about 90k miles using that filter and it is great, sounds awesome. K&N has a big write up about blown MAFs and they claim that they have drastically over oiled their filters and never blown a MAF.

I think Nissan has found a way to charge for a service they should provide for free. I love this concept of your emissions has a issue, so we need you to pay us to fix it, because we screwed it up when we built the car. they are REPROGRAMMING the ECU, what is wrong with the original program.

The MAF on the Maxima uses a heater to heat a transistor, it then measures the power required to keep the transistor at a certain temperature, the more power it requires the more air, or the colder the air is that is moving across the transistor, more air or colder air, means more fuel is needed. Since colder are is denser air.

I'd bet the new MAF has a new transistor, maybe one that doesn't get as hot as the old one that burned out so easily, so they need to reset the parameters in the program. So why am I paying for this, I bought a car that was supposed to run properly, if I take the car in, they get the opportunity to screw me on some service, lets say an oil change, I'll pay for that and they can reprogram my ECU for free, they just plug it into the plug under the dash and run a program on it, why does that merit a diagnostics and reprogram fee.

I love my Maxima, but Nissan sucks, they screw their customers over. I buy a car from them, I EXPECT 100k miles with nothing more than brake repairs, and the first set of rotors should be on them, not me, or they should tell me going in, our rotors only last 35k and you will need to replace them, MAFs go for 50k, then we are gonna soak you for $800 for a new one. And by the way, our Ignition coils are crap, our crank and cam sensors are designed to go bad before 100k, if you even look under the hood, it voids your warranty.

Thank God for the Internet, and maxima.org or we would all be at the Mercy of Nissan Stealerships.

I have owned 4 Maximas, I still have 2, both 2000 SE's, one 98 SE and one 96 SE.

As far a MAF replacement, you will need a 10mm socket and a ratchet. Maybe a screw driver.

Don

 

I replaced my MAF and the maxima 2000 was almost back to normal. But it does give a rough ride specially on a warm start and when the ambient is in the 40s and 50s. I took my car to the dealer for an ECU reprogram. They first told me that the person who replaced my MAF did not know what he was doing. According to them the problem was with the plugs and coils. Any way I asked them just to reprogram the ECU and paid 120/ for it. But I still have my problem. How do I know whether they actually reprogrammed my ECU? Is there any DIY ways of reprogramming the ECU?

Thanks,

jantony