ppborceb

I replaced the O2 sensor, but the service engine soon light didn't go off.
I would appreciate it very much if someone would tell me how to cancel the light.
Thanks,
PPB
20160919.1.180100

Knucklehead39

Disconnect the negative terminal of the battery for 10 seconds. You will have to reset your radio presets.

ppborceb

Hi Knucklehead39,
Thanks for the suggestion...
I did it, but it didn't work... the light is still on just as bright as ever.
I could use some more suggestions from you guys/gals.
PPB
20160920.2.184000

Knucklehead39

I should have said leave the battery disconnected for 30 seconds, not 10. If you left it off for at least that long, it sounds like either there's something else wrong or the connection is bad. Make sure the plug is solidly connected. Why did you replace the oxygen sensor? Did you get a code 13 from the computer, or were there other symptoms?

Camaro86IrocZ

iTrader: (1)

Could always cancel the light by simply removing the bulb...

But the best option is to get your Light Flash Code and continue to diagnose the problem until it is resolved..

Knucklehead39

As the above says, you need to find out what's wrong. There are plenty of discussions on line of what to do when the check engine light comes on. Though written for W-bodies, here's a good one:
http://www.seanster.com/scantool/ecm-codes.html

G.Penrod

I would try and pull out your ECM and verify that your PROM chip is fully seated. When I bought my current Camaro, the SES wouldn't go out and the flash codes wouldn't work. I pulled ECM and realized the PROM wasn't fully seated. I pushed it in and the light went out and the flash codes worked.

ppborceb

Hey Knuckle,
I did 10 seconds just as you suggested, but now I'll try 30.
I don't know what you mean by 'make sure the plug is solidly connected', and I didn't get a code 13 from the computer because I didn't connect anything anywhere, and furthermore I wouldn't know what to connect where.
Do I sound like a 'newbie' that doesn't know what I'm doing... because I am!
I replaced the O2 sensor because everyone said that 90% of the time that is the problem so I just went ahead and replaced the sensor.

Hey Camaro,
Or, I could put a piece of black tape like 'Click and Clack' use to recommend!

Thanks guys,

PPB
20160923.5.122400

Knucklehead39

Don't apologize for being a newby -- everybody was one once. When I said make sure it was plugged in, I was talking about making sure the new oxygen sensor was securely plugged into the wiring harness. If disconnecting the battery >30 seconds doesn't shut off the light, then the O2 sensor wasn't the problem. In post #6 above I suggested you follow the instructions in a web site to obtain real data on what's wrong. You need nothing more than a bent paper clip to run the test. Connect it to the top right two contacts in your computer link (under dash to right of steering column) and follow the directions. Let us know what the light blinks.

ppborceb

Hi guys,
I'm finally back after reading, re-reading, and re-re-reading the link in #6 and following Knuckle's instructions for the paper clip insertion and BINGO
I get 12,12,12,34,34,34,12,12,12!
Now all I have to do is make sense regarding the MAP explanation.
Also, I removed the ECM fuse, waited a few minutes, put it back in, restarted the car, but the light came back on and stayed on!!!
Now WHAT?
I need more help guys.
PPB
20160926.1.112900

paulo57509

The ECM is expecting input from the MAP sensor and it's not getting it. So the ECM turns on the check engine light.

Locate the MAP sensor (I can't help you other than it's under the hood) and make sure the vacuum line and electrical connector are hooked up to the sensor.

The map sensor looks like this (click on the little images):

http://www.rockauto.com/en/catalog/p...le.com+URL+%2F

ppborceb

Hi Paulo,
Thanks for the information.
Now, I'll go out to the garage and try to find the little 'bugger', but as you can see from the prior postings, it's going to take a while because of my inexperience.
PPB
20160926.1.153800

Knucklehead39

Google is your friend. Just Google:
map sensor location gm 2.8 v6

If that's the wrong engine, change the ID.

ppborceb

Hi GPen,
I don't know where the ECM & prom chip are located AND I don't know what they look like either... any guidance would help at this point.
PPB
20160926.1.172200

Knucklehead39

See Paulo post above. Code 34 means a bad/disconnected MAP sensor. I would order a new MAP sensor for your car, look at the link I posted to find your MAP sensor, and replace it.

ppborceb

Hi Knuckle&Company,

Well, I'm finally back after looking for that MAP/MAF under the hood, but now I'm confused about what I am supposed to call that little 'bugger'.

I was reading the Haynes manual and I'm seeing two explanations for code #34.
One says after 1989, it's called a MAP and the other says 1989 and earlier it's called a MAF. So, my question is are they really the same, but only called differently?

Also, I'm still not sure that I'm looking in the right place, and I'm sure that someone will steer me in the right direction and then I'll go and get MAF/MAP.

PPB
20160929.4.162100

OrangeBird

iTrader: (1)

Before and including 1989 , the engine was a 2.8 and used a MAF (mass airflow sensor) mounted in among all the factory plastic/rubber intake piping that runs from the factory air cleaner to the throttle body . Is the entire factory air inlet system from air filter to throttle body still in place ? And hopefully not removed for some dinky little useless "cone of death" K&N filter slapped onto the end of the throttle body ? If so , you will find your MAF is , after a 90ish degree bend , the big plastic pipe leading away from the air cleaner and headed to the square plastic box just behind the top of the radiator . It will have a wire harness going to it with 3 wires in it . There is unfortunately no "field test" for the MAF , as long as two of the 3 wires are +12V and ground , with the third being a 5 volt data line from the ecm , then yea your MAF is likely toast . Do NOT buy a $99 autoparts "special" rebuilt MAF or you'll be sorry , do a bit of research on what's known good these days (It used to be Bosch , but i'm not so sure anymore) and buy good and buy once .

PS , I'm pretty sure that in 1990 , when the 2.8 became a 3.1 is when it went from MAF to MAP , just to let you know why the same code could come to mean two different parts ......

ppborceb

Hi All You Helper Guys,
I'm finally back after reading, searching, and watching YouTube videos regarding cleaning, testing, replacing, and many 'how-to' videos about MAF sensors.
After seeing how expensive new MAF sensors were going to be, I tried to clean the MAF with CRC mass air flow sensor cleaner; But, first what a job to get it out!
And of course, it didn't work... still got code #34.
Now I'm trying to figure out what this 'ecm' thing-a-ma-gig is and what to do with it.
And of course, I have to find out where it is and how to get at it.
Help guys!
PPB
20161005.3.100700

ppborceb

Hello Again!

Well, I'm back and the light is OUT after following your recommendations of BUYING A NEW (NOT A REMANUFACTURED) MAF SENSOR.
So, I want to thank Knucklehead39, Camaro86IrocZ, G.Penrod, paulo57509, OrangeBird.
All of your suggestions were very helpful to me and I hope that in the future, I might be able to help a newbie like me.
Again, thanks guys.

PPB
20161025.2.141100

Knucklehead39

Glad to hear it worked. We're all newbies at some time or other (some for longer than others . . . . . . ).