oxygen sensor question

I have a 99 blazer zr2. Someone told me they think my oxygen sensors need replacing. (Probably do...I'm at 109k miles). How many of these are there in my blazer, and how easy are they to find and replace? Does anybody know about how much they run in price? Thanks for all the help! This Blazer has been a funds drainer lately!

Well my 96 silverodo had 2 O2 sensors and i went to the delership for the first one it was $130 and after i swallowed that i decided to go to napa auto parts and got the second one for like $ 35 they are not hard to put on

You will have 3 or 4 O2 sensors.

1 or two in the exhaust manifolds.

One before the cat convertor

1 after the cat convertor.

Why do you think they need replacing? Did you get some engine codes?

Somebody told me that was the most common reason for a check engine light to come on. I just had the fuel pump replaced, as well as all spark plugs, distributor cap, and rotor, and the timing adjusted, and this thing is still taking a long time to start all of a sudden, and intermittently. So, I turn the key and have to hold it longer than normal to get it to start. Someone told me it is probably the O2 sensor, as they go at 100k, and I'm at 109k. Sound right?


You will have 3 or 4 O2 sensors.

1 or two in the exhaust manifolds.

One before the cat convertor

1 after the cat convertor.

Why do you think they need replacing? Did you get some engine codes?

As I asked before, DO YOU HAVE ANY CHECK ENGINE LIGHTS?

HAVE YOU GOT THE CODES READ?

Please understand that the engine light means there is a computer code that can read to find the actual problem right down to the sensor.

Don't go and replace everything. GET THE CODES READ.

The service engine soon light comes on frequently, and has recently begun flashing sometimes. When it flashes, it will stop after a few minutes. Then, it goes solid. I will get the codes read. I think I can get a machine from Checker Auto Parts for free (just a deposit that I will get back). Thanks for the advice!

AutoZone will also read them for you.

You need an OBDII scanner.

Thank you for that great advice! I went to Autozone, and they read them on the spot for free and it was so fast! So, the codes they told me was that there was a misfire in cylinder 1 (he said likely it needed a tune up, which I have just replaced the spark plugs, distributor cap and rotor, and had the timing adjusted). The other code was saying there was something wrong with the throttle position sensor. Does anybody know what that is, where it is, and how easy it is to fix/replace??


AutoZone will also read them for you.

You need an OBDII scanner.

Can you give us the actually codes that were displayed and not Autozones interpretation?

I wish I could. The guy just read them off to me. I remembered what he said and wrote it down, but he didn't tell me the code numbers... :(

This is where you should have a Haynes or Chilton repair manual to help you.

They are about 10-15 bucks and have all the information about your truck and how to repair.

I would suggest buying it and swapping out the TPS yourself and saving huge amounts of money.

Thank you!! I surely will. I have been MEANING to, but my mind has been so swamped with trying to figure this whole thing out, I keep forgetting to buy one! THANK YOU!!!

If you have a laptop you can opt to have a better OBDII scanner than what is offered generically through your local run of the mill parts store.
http://obddiagnositcs.com Download the software for FREE and you can buy the interface for $88 bucks. It does a lot for the money! And still cost less than the units offered through Actron or Equus. However it's not a Snap-On Modis or a GM Tech 2 either. -Chris

oops....correction misspelled....
http://obddiagnostics.com also for O2 sensors....try http://www.oxygensensors.com I would opt for the denso brand.

but remember, his O2 sensors are not the problem.

He needs a tuneup and a new TPS.