99 blazer ses light

I recently had oil changed and all was good. At the time I also replaced air cleaner, and added some coolant. A week later I went on trip and after going about 200 miles on interstate the SES light came on and stayed on. Filled tank and light went off. on return trip I went about 50 miles and light came on. Reseated Gas cap and no avail. Any suggestions?? Please

Pull the codes and tell us what they are. Autozone will read the computer for free - but do not buy into their assessment - get the codes themselves. Usually they will start with a "Pxxxx" number. Post them here, and someone can answer your question quickly. Good luck!

SES light will come on when a monitored sensor fails 1,2 or 3 times depending on sensor and will turn it off when it passes a set number of times. So the light didn't go off because you got gas, it probably went off because the system did a self test on startup.

After the car wasnt used for 3 days, I started it up to go to Auto Zone and the light was off. They said that they couldnt give me reading unless the light was on. Been OK since. Will keep eye on it.
Thanks for all your help.

Gee, how nice of them. The code can stay in the system for a week, sometimes even more. Even when the light goes out, it's still in history. I work like that all the time.

I know that my 89 Blazer kept codes for a while and could still be read. I think that the tech that I talked to just didnt want to do it. I will try a different AUTO ZONE as there are others around.
Thanks

Go back to the autozone you went to in the first place and tell the counter monkey to get off of his fat ass and scan the code.

All codes are stored even when the light goes off.

just a little note. feel lucky you guys can go to autozone and still have that done for you. The ones where i live in California used to do that for free and I don't know if they just didn't want to anymore or what (they said the local mechanics had complained so much they were forced to stop) but i finally just went out and bought my own scanner so I didn't have to pay the 100-120 dollars the mechanics were charging to have this done.

It is their policy to do it.

Stopping it because of their local competition sounds like bullshit to me.

They don't want to give the business to the local guys.

Today I got the code read out, P0101 which seems to indicate a airflow problem. correct?

Mass Airflow Sensor *Performance*... Note it says performance, so think of what could be messing with your MAF sensor.

Said you just replaced the air filter too...

Double check your work. Make sure that the airbox is sealed around the filter properly, and that the filter is seated correctly too - are all of your clips and screws in place?

Are all of your PCV tubes in place? And most importantly - didn't bump the MAF around too much while doing all of that? Worst comes to worst, it may be cleaned with carburetor cleaner and then put back in place. Be mindful to not damage the screen or the element inside of it...

Reset the computer by lifting off your negative battery terminal for 10 minutes, reconnect - drive as you usually do. Hopefully the SES will stay off for you. :licka:

DTC P0101 Mass Air Flow (MAF) Sensor Performance

I have seen many times, if the breather tube on the rear of the air cleaner outlet duct is disconnected, it can set this code. I am assuming that there is no performance concern.

Today I removed and reinstalled the air cleaner. All looked fine, I looked at all tube connectors, again OK, Still cannot duplicate problem. Will reset the computer and wait for the next problem. Thanks to all for the useful information.

Thanks Ricksza for your help. Sometimes I will disconnect then reconnect. possibly the breather tube was misaligned and got realigned when I did what I did. Thanks again.

The reason in california for places like Autozone not being able to scan codes anymore was because of the auto mechanics unions. Yes they bitched a lot and said that was mechanics work (BS) so everyone including the state government caved in before the unions (as usual, I hate unions) and therefor they aren't allowed to do that anymore.

Today I got the code read out, P0101 which seems to indicate a airflow problem. correct?

That is a Mass Air Flow Sensor Performance problem.

Remove the MAF and clean it with TB cleaner. The sensor wires are gunked up which is pretty common and with this treatment, it will be fixed.

Is it legal to sell the scan tools in Calif? Surely you can buy your own if you want to.

In Calif is it legal to own your own scanner?

In Calif is it legal to own your own scanner?

If it is illegal to sell a scanner, there must be a lot of SnapOn, MAC etc. dealers running from the law.

Last I knew, it isn't illegal to sell, rent, or own a scanner in any of the states in this here union. I would bet Canada is the same. It is a tool.

I have a friend vacationing in LA over the holidays and he insists that he can get a REAL good price on a MT2500. If he isn't on the airplane on Saturday when I go to pick him up, oh well, quess he's in the pokey.

Yeah, you can own your own scanner, that's shouldn't be a prob