o2 sensor symptoms?

97 blazer, vortec motor, 135K, runs great,kept up service schedule,new plugs, air, oil and fuel filter, grease, fluid levels all of it. While on vacation it started bucking as if it ran out of fuel or lost spark. Have since then replaced plugs, air and fuel filter, no improvement. Had it on computer and it says 02 sensor going bad. Are these symptoms of a sensor going bad? Some say yes and some say maybe. Any feedback would be appreciated as would any suggestions. Thank you

Let me guess a lean o2 code?? Please have the fuel pressure checked before you waist money on the o2 sensor

1997 = Ignition Switch gone bad.

Replace the ignition switch before you replace ANYTHING.

It is in the steering column and fails on almost all 1997 blazers. And yes, it can cause the O2 sensor code amongst other weird things like tranny codes etc...

All fixed by a new switch and computer reset.

Thank you for your speedy response. Your input is greatly appreciated. These are things that have crossed my mind but when put under the influence of a computer it tends to over ride any common sense you may have left that tells you to go to the obvious. Thanks again guys, you have brought me back from limbo and into the world of human logic. Will keep you postedd on results so anyone else with these problems will be able to solve them without going into the bowels of cyber space. TTYL.

Excellent, keep us posted.

Hi, are there any web-sites that have diagrams of the ignition switch? Thanks.

There is a photo at advance auto parts

Thank's, on my way.

Hi y'all. I STILL have this 97 Blazer with a new set of plugs, new air and gas filter and a new ignition switch and the car still thinks it's a horse, it still likes to buck periodically. The only thing it does'nt have is a fuel pump pressure check which I will do tomorrow at the same time I look for a place to plug in one little three prong plug. The old switch had one too that I don't recall un-plugging so, could anyone out there tell me, is there a three prong plug just left hanging around for some unknown reason or am I missing a plug in somewhere? Thanks again to all and have a nice Christmas. I think I'm getting an 02 sensor or mass air flow sensor for Christmas. O'boy !!!!. TTYL

So there is a connection missing somewhere?

Also, spray throttle body cleaner through your MAF sensor with it out of the vehicle to dissolve the black gunk off of the sensor wires.

Be careful, the sensor is sensitive.

Hey guys. So I guess I will look harder for a 3 prong receptical. Fortunately the lady across the street from me has a blazer just like mine so if push comes to shove I'll take a look under her dash to see what I see, if she will let me and will try the cleaner on MAF sensor. Let you what happens and thanks for your help. Sensitive sensor huh - uh oh. TTYL

Hi, I'm back, well it wasn't the ignition switch or the mass air flo sensor, I put new one's in. so I took it back to the chevy dealership where I bought it a year ago and they can't fix it or find the problem they just checked it and test drove it,threw up their hand's and charged $113.00 and it bucked on the way home, arrrrgh! any clue's? cheap one's hopefully. Thanx and Happy New Year.

Did I or did I not tell you to get the fuel pressure checked before you WASTE any money throwing parts at a problem. I just dont understand you people. You all want to save money by doing the work your self but you will toss tons of cash on parts just for the fun of it.
Did you ever get the pressure checked???

yes, I did and with all due respect to you and all others, I do appreciate all your info. but please, I do not live within the perameters that allow me to make two or three trips a day to the mechanic. It is a 100 round trip miles for me to go to the mech.. What I am saying is that at this point I rely a-lot on the info. that I get from people like you and this forum and I am sure that between people like you, me and the others like ourselves can save each other time and money so,,,,,,lets go with what we have so far alright. I have a 1997 chevy s10 blazer. It acts as if it is either losing spark intermitently or, funny I/you should think of this, a fuel delivery problem. My next move is, a fuel problem, starting with a new fuel cap on up to fuel delivery prob.'s. and like I said, I am relying on people like you, us and me to solve these stupid little prob.'s that p's us off so bad cuz the f'n cumputor that is suppose to tell us everything is nothing but a piece of -04595769394u that cannot solve the problem this car is having sooooooo what the heck is the sense??? Thank you all for your input and like I said, between the bunch of us we will find the problem and will share it. Thanks a lot guys and a HAPPY NEW YEAR TO YOU ALL!!! TTYL Cblazer and Chevy,,,,what the hell is the matter with you???? c'mon.

What ?????????????????????????????????????????????????? ?????????????????????????????????????????????????? ?????????????????????????????????????????????????? ?????????????????????????????????????????????????? ?????????????????????????????????????????

yes, I did and with all due respect to you and all others, I do appreciate all your info. but please, I do not live within the perameters that allow me to make two or three trips a day to the mechanic. It is a 100 round trip miles for me to go to the mech.. What I am saying is that at this point I rely a-lot on the info. that I get from people like you and this forum and I am sure that between people like you, me and the others like ourselves can save each other time and money so,,,,,,lets go with what we have so far alright. I have a 1997 chevy s10 blazer. It acts as if it is either losing spark intermitently or, funny I/you should think of this, a fuel delivery problem. My next move is, a fuel problem, starting with a new fuel cap on up to fuel delivery prob.'s. and like I said, I am relying on people like you, us and me to solve these stupid little prob.'s that p's us off so bad cuz the f'n cumputor that is suppose to tell us everything is nothing but a piece of -04595769394u that cannot solve the problem this car is having sooooooo what the heck is the sense??? Thank you all for your input and like I said, between the bunch of us we will find the problem and will share it. Thanks a lot guys and a HAPPY NEW YEAR TO YOU ALL!!! TTYL Cblazer and Chevy,,,,what the hell is the matter with you???? c'mon.

You need to start listening to us more. He is right, check the fuel pressure yourself, we aren't telling you to go to a dealer everytime.

YES, I did have the fuel pressure checked - okay I will check it myself. I am listening !! That is how I ended up with a new ignition switch. The trip to the dealer was my move and learned that their mech. is'nt worth his salt - gambled, lost. Onward. A fuel pressure check is going to tell me wheather or not I have a fuel delivery problem what about from that point on? I'll be back - ttyl, c-blazer.

Replace your fuel injection or maybe the complete motor and it should run better.

Replace your fuel injection or maybe the complete motor and it should run better.

Kalamar, if you are not going to seriously help, don't post.

I have seen you thread crapping lately and it is getting really annoying.

YES, I did have the fuel pressure checked - okay I will check it myself. I am listening !! That is how I ended up with a new ignition switch. The trip to the dealer was my move and learned that their mech. is'nt worth his salt - gambled, lost. Onward. A fuel pressure check is going to tell me wheather or not I have a fuel delivery problem what about from that point on? I'll be back - ttyl, c-blazer.

Come back and tell us the fuel pressure when running and with the engine off with the key to the first position for fuel pump prime.

Hello, Ok I finished the pressure check and the PSI read's 60 with the engine off and the key in the first position, it read's 54 with the engine running, seem's hoyle to me. I now have the ignition switch all undone again [way undone] and still can't find where that 3 pronged plug guzinta, got a Hayne's manual and a library card, neither one show where a plug-in like that would be and can't locate an empty recepticle anywhere around where it might go. There's about 5-6 in of snow out there but at least the sun's warm. for another 30 minutes +-. BB.

54 psi running is on the low side and could cause a bunch of drivabilty problems

54 psi running is on the low side and could cause a bunch of drivabilty problems

My thoughts exactly, sounds as though the pressure regulator is bad.

Since checking the fuel press and being advised that 54 psi running is on the low side I have put about 400 mi. on it and it has run good not fine, good - little ruff but does'nt seem to buck anymore and mileage has dropped some. Will check press. reg. and will keep you posted. Been doing alot of 4 wheel driving, not off road, due to snow so I am sure that has alot to do with mileage drop but still should idle smoother and not convinced the bucking problem healed itself ! Will get back to ya. Cblazer

... I now have the ignition switch all undone again [way undone] and still can't find where that 3 pronged plug guzinta, got a Hayne's manual and a library card, neither one show where a plug-in like that would be and can't locate an empty recepticle anywhere around where it might go. There's about 5-6 in of snow out there but at least the sun's warm. for another 30 minutes +-. BB.

I am by no means an expert, but I had my dash torn apart looking at my ign. switch and the 3 prong thingy was hanging there as well. This would be the original that was in there, not ever monkeyed with to my knowledge. I'm thinking that it doesn't plug in anywhere.

Since checking the fuel press and being advised that 54 psi running is on the low side I have put about 400 mi. on it and it has run good not fine, good - little ruff but does'nt seem to buck anymore and mileage has dropped some. Will check press. reg. and will keep you posted. Been doing alot of 4 wheel driving, not off road, due to snow so I am sure that has alot to do with mileage drop but still should idle smoother and not convinced the bucking problem healed itself ! Will get back to ya. Cblazer

What was the O2 code you got when you hooked it up to the computer?

blazermadness, I am convinced that that 3 pronged plug is there to confuse us, me, or you. I dunno but, Thank you for looking! The code, after being hooked up to the computer was P0102, mass air flow sensor circuit-low frequency detected according to the Haynes repair manual. Will be waiting for response, talk to ya later, cblazer

Well, you will need to pull your MAF and clean it with TB cleaner so the you can dissolve the gunk off of the small wires inside that measure the airflow.

also, make sure the MAF is plugged in properly.

blazerlt, will do that and let you know 1-18-05 but if the maf is new, should cleaning the small wires be necassary?

If it is new, no is shouldn't require service.

what should the pressure be?

What pressure?

The fuel pressure, what should it be?

The fuel pressure, what should it be?

For what engine?

94 4.3L Vortec 115,000 miles

Vin W or Vin Z?

UH hold on......vin is a W I guess for CPI right?

Vin W = 56-61psi with key on but not started.

cool will check this weekend and let you know!

Blazer seems to be running okay not quite up to my expectations but does'nt buck and jive anymore and don't really know the reason or what cured it but I go from one vehicle to the next around here trying not to neglect one vehicle for the other. Have a 74 ford f-250 that just keeps going and going when all others fail, great truck, bought it new and have put it through hell and it still looks great and runs great. I have a real nice 68 VW westfalia camper bus in great condition for it's age that needs very little to bring it up to original primo condition and is for sale if anyone is interested also an 88 buick that was given to me. Nice car. needed timing chain, runs great now, wife loves it so as you know they all need attention every know and then and tends to keep me pretty busy.I will keep in touch and have enjoyed being a part of this forum. It has been informative and very helpful. thanks to all and like I said, will keep in touch and you all do the same, ttyl cblazer