My o2 sensor went bad...CEL light was on...replaced it and, woah, more power, smoother delivery and way better gas mileage.

I bought this lil Protege about a year and a half ago...did some some routine maintenance and just drove the tar out of it. It's always gotten around 30-32mpg around town. Freeway, maybe 35mpg. I'd start looking for a gas station around 300 miles, even pushed it to 360 one time.

Well, the check engine light came on. I took it down to the Mazda dealer to see if they would plug in an OBD scanner and tell me the code...pay maybe 15min to half an hour of labor. They wanted $85 for "diagnostic time". I told them to stick their scanner where the sun doesn't shine.

Called a friend in San Antonio (about an hour away) who owns a garage. He said he'd read it for free (but they usually charged $37.99...what a rip the dealer is). Turns out it was the o2 sensor.
Paid $92 for a new one, took it home and plugged it right in.

The car runs noticeably better. I've used a little over a 1/4 of a tank and gone 160 miles. I was getting about 150 miles on 1/2 a tank before. I'll be curious to see what mpg end up being on a new full tank.

 

That is a neat idea. I do not know what you have for the engine, but the best I ever gotten out of my 1.5 liter was 420 miles.

 

damn 16's ,, I tend to average about 320 minimum to about 370 maximum
Bruce

 

you guys get some good gas mileage.......
Best I ever did was 320.....
But then again, i think the Low Gas Light only came on once since I had the car, I like havin gas in me car...

How many miles are on your Pro when you changed your O2 sensor????? I got 58,500 on my '97 and i get a CEL every now and then....

 

I have 92k on the car, and have yet to change the o2 sensor, where did you order your sensor for so cheap , was it an online store
Bruce

 

Got a direct fit OEM Bosch from O'Reillys. None of that generic sensor, soldering wires crap for me. It was on "sale" for $92. List price was $152.

Tried Autozone first but they didn't have any in stock. They tried to special order it but it turns out it's not even available to order.

 

damn, my 98 1.5L has over 90,000 mi. and i'm averaging 320-340mpg. of course, i live in CA where they're not exactly giving gas away. anyone else notice when you run the A/C on a 1.5L u can barely get the thing to move? might be time to change my o2 sensor too.