I-30 mass air flow sensor

[lloyd]

I have a 2000 I-30. Dealer says mass air flow sensor needs replaced($140 + 4 hours labor) because I used aftermarket air filter. Could it just need cleaned?I don't have a manual. Where is the MAF and how do I change it? Are special tools required? Could it possibly take 4 hours?

[maxnix]

And the after market filter was a ....?

Brake cleaner can usually clean it. It is just after the air filter. Be careful with the connector and don't touch the sensor element when you clean it! It would be wise to have any new replacement gaskets required on hand for reassembly.

Do a search and read posts here first.

Welcome to the board.

[Q45tech]

There maybe [seem to remember] a TSB on 2000 and later MAF which require that you reflash the ecu when replacing unit........that maybe the extra hours of labor.Requires a Consult II and the software update.

The parts price looks too cheap?

[autotech43]

The theory behind the aftermarket air filter. The mass air flow sensor on that model is not of the hot wire type, in another words, it doesn't have a heated wire after engine shut off to clean the sensor. Infiniti is telling us that SOME aftermarket filters may have too much oil in the fibers, therefore if the sensor plate gets saturated with oil, it will cause a severe lean running condition resulting in a number of driveability concerns. I wouldn't recommend spraying any type of cleaners, solvents in that particular air flow sensor. The sensor price was right above the retail $600.00 range, Infiniti has reduced the price to what was mentioned in the previous post of around the $140.00 range. Q-45 tech mentioned the reprogramming of the ECM (electronic control module). Technicians have to take the tech bulletin and match up the current ECM number to see if it falls in the category for the reprogramming to an updated number. We have replaced numerous mass air flow sensors regarding this concern. K & N filter users need to use caution when cleaning and reoiling those type filters to not oversaturate the filter with oil.

[maxnix]

Great technical posts, fellas! No free lunch, is there?

[vtfrankenstein]

Any problems with the MAF sensor. If you get the code for MAF. I would always stick with an OEM air filter. I have seen MAF code and the car has aftermarket filter. replaced filter cleared code and on their way happy with a cheaper bill.

[Q45tech]

Sometimes the cotton fibers come loose and intwine around the sensing element. Mixed with oil they stick like glue insulating the sensor --sluggish/inaccurate response to changes........use your microscope to examine.

Just part of your punishment for believing marketing hype.

GM and Ford have recent TSB that voids warranty on MAF with any changes to air box or filter.

Toyota used Karman Vortex air flow sensor which doesn't use heated element but ultrasonic air swirls so they never have this problem with filters. But they have inaccurate high flows compared to MAF hot wire type.

[Q45tech]

The problem with MAF is you are only given wide ranges of voltages to check function..........1.0-1.4 volts at idle.

http://www.gatewaycleanair.com...f.htm

"MAF Dirty WireA problem part that has become increasingly common is the hot-wire style Mass Air Flow used in many vehicles today. This is often caused by improper air filter service, which eventually allows dirt or filter fibers to wrap around the MAF hot wire sensor elements.

This figure of the scope test waveform is showing the dirty snap throttle check as well as the cleaned and new replacement unit. There has been some discussion on Internet discussion forums as to the proper method of repairing the unit, with some votes for replacements and others for cleaning the unit using some caution. Our testing shows that the new unit usually has a much better response, though we have also cleaned quite a few with great results."............http://www.babcox.com/editorial/us/us10038.htm

[Q45tech]

As you see from the above even a properly cleaned unit is NOT a new unit as far as snap [acceleration response is concerned].

I once tried to measure 3 different MAFs on my Q with Consult .....every one was slightly different, in keeping with the 3% [?] published accuracy of the design.........assumming that cares thru to ecu..........a 3% accuracy in injector pulse width is perfectly fine even 5% [even 10%] richer is ok in acceleration.

What is 3% difference at 4.3 volts............not much less than 0.05 volts............so your measurement accuracy counts.

Short of measuring a MAF on a flow bench you must get to know the exact voltages on YOUR car under different conditions.