Check Engine Light

1997 Grand Am SE, 3.1L V6
101,100 miles

Ok so when I first purchased this Grand Am a few weeks ago I noticed the check engine light on. I took it to Advance Auto Parts where they did a free computer scan, and pulled the codes for the Bank 1 O2 Sensor and the MAF Sensor. My mechanic and I decided give the Grand Am a complete tune up (all the fluids, filters, plugs and wires), and I also replaced the Bank 1 O2 Sensor. But I held off replacing the MAF Sensor and just used some MAF Sensor cleaning spary and cleanded it off a little. After all that work I filled it up with gas and drove it around for a few days. The check engine light was still on. After refilling it with gas again, I noticed the car was only getting a little over 13.4 miles/gallon. I took the Grand Am on the highway a few days ago and the check engine light went out and has been out ever since. Im now getting a little over 20.2 miles/gallon.

So my question is does anyone think the check engine light will remain off? Or should I just go ahead and replace the MAF Sensor? Also, should I be getting more than 20 miles/gallon, or is that about right?

Happy Independence Day All & Thanks

1997 Grand Am SE, 3.1L V6
101,100 miles

Ok so when I first purchased this Grand Am a few weeks ago I noticed the check engine light on. I took it to Advance Auto Parts where they did a free computer scan, and pulled the codes for the Bank 1 O2 Sensor and the MAF Sensor. My mechanic and I decided give the Grand Am a complete tune up (all the fluids, filters, plugs and wires), and I also replaced the Bank 1 O2 Sensor. But I held off replacing the MAF Sensor and just used some MAF Sensor cleaning spary and cleanded it off a little. After all that work I filled it up with gas and drove it around for a few days. The check engine light was still on. After refilling it with gas again, I noticed the car was only getting a little over 13.4 miles/gallon. I took the Grand Am on the highway a few days ago and the check engine light went out and has been out ever since. Im now getting a little over 20.2 miles/gallon.

So my question is does anyone think the check engine light will remain off? Or should I just go ahead and replace the MAF Sensor? Also, should I be getting more than 20 miles/gallon, or is that about right?

Happy Independence Day All & Thanks

Well It's hard to say if the check engine light will stay off or not. For the time being you've bought yourself sometime by cleaning the MAF sensor. Eventually you may need to replace it. On the gas mileage You should be getting around 27mpg on the highway ( with continuous highway driving) if you mix highway and city driving then you'll get around 20-23 mpg. For city expect around 15-20 mpg. This also depends on driving habits and road conditions as well.

ditto 28 hwy 96 3.1 motor although sensor is cleaned you could have reconnected a wire coupling better and to check a maf sensor you could tap on it while motor is running to see if the motor will stumble if so replace it

yea MAF cleaner and maybe some electronics cleaner if you can find some to clean off the inside of the plugs to the MAF on the side... clean all those connections up

well, so far the check engine light is still off. hopefully it will stay off long enough for me to go through the new jersey state inspection. i was planning on changing the maf sensor anyway.

i have another quick question. just before i had all the work done to my car, my mechanic said he smelled gas on my old plugs. he attributed that to the
o2 sensor. he thought my car could have been running to rich. when advanced auto scanned it they said bank 1 o2 sensor was bad and that was causing the engine to run to lean. does that make any sense to anyone? i mean its running much better now, but would a bad o2 sensor cause your plugs to smell like gas, and wouldn't that mean the engine was running to rich, not to lean?

Again, thanks all

OK first off after you replaced the O2 sensor the codes should have been cleared, that could be why the light was still one.
What was the exact codes read for the MAF ?

Fuel smell on the plugs could be your injectors are not functioning properly, and could be the plugs are not getting proper spark due too bad wires/coils/ICM or just needs new plugs. :dunno:

Your mechanic should be able to tell from the tests he performs :rolleyes:

20mpg is about right for your car and mileage, but with a tune up it could increase a little more mpg.

well, so far the check engine light is still off. hopefully it will stay off long enough for me to go through the new jersey state inspection. i was planning on changing the maf sensor anyway.......

Good luck with the inspection... I cringe everytime i have to go! Just don't go if the check engine light comes back on, it's an automatic rejection which you probably know. Also depends on which station you go to you can "bargain" your way though to pass.... or at least i have in the past.... :grinyes: