FAQ: Mass Air Flow (MAF) Sensor Issues?

You are right, the '99 uses a different sensor. There are no later model years for Riviera.

AA wrote:

You are right, the '99 uses a different sensor. There are no later model years for Riviera.

I was referring to later years of the 3800 if someone were to snag a MAF from one of those.

Thank you!

Mikel,

For some reason, I cannot find my own post about the MAF sensor... From what I remember when I cleaned my own last year, there are 2 kinds of "Security Torx" screws, and this stupid thing uses the 'standard' kind. I think it is either #20 or 25.

However, once you unscrew it and gently twist the sensor out of the throttle body, be sure that you spray either MAF or Electronics cleaner from a safe distance, to avoid breaking the filament with the force of the spray... say, 12-15 inches to start with.

Well, good news! I pulled the MAF sensor (regular phillips/flat screws) and cleaned it. The error code is gone and so are the hesitations.

My gas mileage had steadily dropped from 23MPG to 20-21 in the last year. I wonder if this will have an effect.

Thank you all.

Mikel

Great news! Thanks for the report, and let us know if your MPG sees improvement.

Mikel wrote:

Well, good news! I pulled the MAF sensor (regular phillips/flat screws) and cleaned it. The error code is gone and so are the hesitations.

My gas mileage had steadily dropped from 23MPG to 20-21 in the last year. I wonder if this will have an effect.

Thank you all.

Mikel

Hmmmm............. if your MAF was installed with common screws I wonder if someone (PO orPO's erstwhile mechanic) was in there before you, and why?

Albertj

Is it Year dependant as to what kind of screws / fasteners are installed.???

Just curious.

What year is your car Mikel.?

I'm planning to remove mine soon for cleaning. After the Heat Wave is over. No need to sweat my butt off right now.

Mikel wrote:

Hello,
My '97 Riviera has been having some infrequent hesitations...

Mikel

Gotcha' Rick!

The only one I've heard of having 'normal' screws is Ilan's '95... Mikel's '97 should definitely have had the Security Torx like mine. I bought a set of the bits off Amazon for dirt.

It's a 97. The two screws were phillips with an extra flat slot. I was done in 5 minutes...

Well...on top of my general frustration where my Riv is concerned after putting in the parts I got from NAPA the damn MAF failed in about 45 min!! Talk about being pissed...not to mention they sent me home with the wrong O2 sensor!! Not even for a buick,it was for a stinking Toyota!!

madrivage wrote:

Well...on top of my general frustration where my Riv is concerned after putting in the parts I got from NAPA the damn MAF failed in about 45 min!! Talk about being pissed...not to mention they sent me home with the wrong O2 sensor!! Not even for a buick,it was for a stinking Toyota!!

Well... if the MAF failed they should replace it but you should also look for a short in the wiring to it. You ahould also look at your airbox modifications - are you leaking air past the filter?

Also, you gutted your aribox and installed a K&N filter... did you overoil it or use an oil diff from the K&N? read this from K&N...

http://www.knfilters.com/maf/maftestresults.htm

about failing MAFs with K&Ns.

Also see this site:

http://www.niehoff.com/techtips/15premass.html

about MAF failures due to problems with the throttle position sensor. Didn't you replace the TPS? I forget. Anyway, if you did not you might want to check tis operation with a meter and if you did you might want to check the wiring to it.


You mighgt want to un-modify your air box until you get the rest of your problems fixed...

Albertj

Our 96 Riv Check Engine light came on with code P0102. Anyone have any ideas as to where to start looking for the problem? Thanks so much!

P0102 MAF Sensor Circuit Low Frequency.

- Check all the wires at the MAF for any corrosion/breaks.
- Remove the intake tube from the TB and check the inlet screen for any damage and/or blockage.
- Check and see if you can hear any vacuum leaks at the Intake Manifold, TB, or EGR pipes/flanges.

These are visual checks. If you want to dig further, and feel safe doing so, I can post the electrical tests for you. Most of the time, MAF sensors start getting intermittent bad readings when they start going bad. They get a "dead" spot in the frequency range that causes this code to set. You won't be able to see this without a good scanner.

Thanks and will do the visual checks you mentioned, and then may need you to post the electrical tests you so kindly offered. Thanks for the helpful info!

BatMobile wrote:

Thanks and will do the visual checks you mentioned, and then may need you to post the electrical tests you so kindly offered. Thanks for the helpful info!

No problem. The electrical checks are basically just making sure you have the proper voltage and resistance at the MAF plug. Let us know.

Don't know if this was just a coincidence, but the check engine light came on right after we took car through inspection. In NJ starting this month, cars are only tested for exhaust and hooked up to a computer. The gas cap was removed, so we thought maybe it wasn't put back on properly and that was causing the code, but evidently not. Just think it odd that right after being inspected the CE light came on.

I'm not sure what they do during the inspection. I've never had to get one. We're allowed to deplete the ozone here in Michigan.......

Abaddon wrote:

We're allowed to deplete the ozone here in Michigan.......

YOOOUUUU BASTARDS!!!!!! Does Obama know about this?!?

Oh, right, he's from Illinois...

Abaddon wrote:

P0102 MAF Sensor Circuit Low Frequency.

- Check all the wires at the MAF for any corrosion/breaks.
- Remove the intake tube from the TB and check the inlet screen for any damage and/or blockage.
- Check and see if you can hear any vacuum leaks at the Intake Manifold, TB, or EGR pipes/flanges.

These are visual checks. If you want to dig further, and feel safe doing so, I can post the electrical tests for you. Most of the time, MAF sensors start getting intermittent bad readings when they start going bad. They get a "dead" spot in the frequency range that causes this code to set. You won't be able to see this without a good scanner.

Just wanted to let you know that we did all that you advised and have installed a new (not rebuilt) MAF sensor. Seems good to go and thanks so much for your help!

BatMobile wrote:

Just wanted to let you know that we did all that you advised and have installed a new (not rebuilt) MAF sensor. Seems good to go and thanks so much for your help!

Cool beans man. Glad to hear it's runnin (good) again!

Ok guys, so my Dads' 99 PA stalled twice today going downhill. The first time it started back up but the car was shaking and a big cloud of black smoke came out the back, it also set an SES light. After that he used the car all day, and it ran fine, until tonight. He went down another slope and the car cut out again. I believe I can hear the fuel pump buzzing when he tries cranking it over but no start, although the whole car started smelling like gas fumes after a few tries despite no leak. He is currently on route via a tow truck to a shop which is obviously closed tonight and tomorrow. It seems like the FP, but I will scan it first to see what the code is. We are gonna head out there tomorrow to see if we can solve it with a little help from you guys, any ideas!?!

it sounds like a clogged cat.But I know s..t all 'bout diagnosing. but it remindes me of cat probs Ive had in the past. heres a good video on how to test a oxy sensor. dont know if it will help but aside from cutting off the cat and then seeing how she runs,its a good vid.
Bonne chance!

Thanks robo, but wheres the vid?

Edit: Thanks man!