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Replacing the Mass Airflow Sensor

Posted: Sat Apr 19, 2014 11:48 am
by Togemachi
I purchased a Delphi mass airflow sensor from NAPA auto parts and they told me I have to get the ECM reprogrammed. Is this true? I spoke with one repair shop that said you do not need have any reprogramming done. I have a 2001 SLE.

If I don't need to do this, would simply swapping out the sensor be enough? At this point, my car starts, but unless I keep giving it gas, it quickly dies.

Re: Replacing the Mass Airflow Sensor

Posted: Sat Apr 19, 2014 12:54 pm
by Archon
The computer does not need to be reprogrammed when swapping out the MAF sensor.

Re: Replacing the Mass Airflow Sensor

Posted: Sat Apr 19, 2014 1:06 pm
by vogie01
Have you cleaned the MAF to see if it runs differently? I would clean the old one first before you put the new one on.

Re: Replacing the Mass Airflow Sensor

Posted: Sat Apr 19, 2014 1:49 pm
by RJolly87
How have you confirmed the MAF is in need of replacement?

Re: Replacing the Mass Airflow Sensor

Posted: Sun Apr 20, 2014 8:54 pm
by Togemachi
Thanks for your advice. I took it into a shop a few months ago because it was experiencing a hard start. It would die if you didn't put your foot on the gas for the first few seconds after starting it. So I took it in after a couple of months to get diagnosed. They decided it was probably the MAF, but I didn't have the money to replace it at the time. I bought an aftermarket MAF (can't remember the brand and whether it was refurbished or not), but that actually made the car run much worse. So I took it back--not knowing where to get the part next (I had thought to get an OEM, but didn't have the $300+ to pay for it).

The old MAF at least kept the car running reliably, just as long as I revved up the engine a little, right after starting it up. A few more months went by (doing this every time I started the car), until recently when the car just died no matter how long I kept my foot on the accelerator. I bought mass airflow sensor cleaner and sprayed it and tested it a couple of times, but the car kept dying. So I gave up on the original part and bought a Delphi MAF from NAPA, only to be told that I needed to "get the computer reprogrammed to adjust for the new sensor." I had been hearing a few conflicting ideas concerning this, but now I'm pretty certain all I need to do is swap out the MAF with the new one. It's stuck at work this weekend, but I'm going to try it early part of this week. I'll let you all know how it goes.

Re: Replacing the Mass Airflow Sensor

Posted: Thu Apr 24, 2014 2:50 pm
by Togemachi
Ok, so I swapped out the original MAF with a Delphi MAF. But it still does the same thing: the engine gradually dies if you don't keep your foot on the accellerator. I'm not sure what to think now: is there some kind of relay or connection I should look check? Should I disconnect the battery to 'reset' the computer? My car is stuck in an underground parking garage, so I'm trying to avoid trying to get it towed out.

Any ideas?

Re: Replacing the Mass Airflow Sensor

Posted: Thu Apr 24, 2014 4:35 pm
by azu
I had same problem, thinking it was MAF but turned out to be a bad spark plug wire. Wires were only 5K old.

Re: Replacing the Mass Airflow Sensor

Posted: Thu Apr 24, 2014 5:02 pm
by Togemachi
I've seen some posts on here that mention disconnecting the MAF and starting the car. When I do this, the car still dies. Does this mean that the problem might in fact not be related to the MAF?

Re: Replacing the Mass Airflow Sensor

Posted: Thu Apr 24, 2014 11:49 pm
by 2000Silverbullet
I just fixed a similar problem with a 94 SSEi. Tried disconnecting the MAF and didn't make any difference. Popped in a used MAF for $60 and it works now.
How is your Idle Air Control motor?

Re: Replacing the Mass Airflow Sensor

Posted: Fri Apr 25, 2014 12:16 am
by nos4blood70
Things I would check: all of the ignition system. Fuel filter. Plugged cat. State of the upper intake manifold, make sure it's not leaking. PCV valve.

Attempt cleaning the IAC which Paul mentioned above. You can use MAF cleaner.

Re: Replacing the Mass Airflow Sensor

Posted: Wed May 14, 2014 2:55 pm
by Togemachi
Thanks for the ideas, guys. It's been in and out of a repair shop since I last posted. I took it in, and they diagnosed it as a fuel pressure regulator issue. They replaced it, and I drove it for a few days before the same exact problem resurfaced.

So I took it back in. They say it has an engine misfire code in addition to a code on the catalytic converter (I've replaced the cat twice (I'm buying cheap ones, apparently) in the last few years, as well as replaced the O2 sensors). I'm not sure that is the problem or not at this point, since the starting problem started long before the cat code appeared.

Anyway, they say they aren't sure what the problem is right now, but after I described how the engine dies if I don't step on the accelerator after starting up, they suggest I replace the throttle position sensor or the idle air control valve. I'll check the IAC after I get it back and attempt to clean it, but before I start going ahead and changing out a bunch of parts, does any of this sound like it could be the cause?

The fuel filter is relatively new (6 months) and there does not appear to be any leaking from the upper intake manifold.

Re: Replacing the Mass Airflow Sensor

Posted: Wed May 14, 2014 3:30 pm
by 2000Silverbullet
Have you checked your fuel pressure? How full is your fuel tank when the problem occurs?

Re: Replacing the Mass Airflow Sensor

Posted: Wed May 14, 2014 3:51 pm
by MrPOPE
My bonne would die on start up once warm without reving it first with every MAF i tried....when i just disconnected the MAF haven't had a single problem since with the car. Either every MAF i tried is defective OR the ECM is just not reading the MAF correctly but runs fine in simulated mode with the MAF disco'd