94 Mazda B4000 4.0?

[dbailey]

My son has a 94 Mazda B4000 4.0 4x4 and I am told they are basically the same as the Ranger. True? I need to replace the O2 sensors and just wanted to sanity check how many there are? Not sure when if ever they have been changed and I understand they will impact the gas mileage bigtime. It gets fairly pitiful mileage and being a 4.0 I know that is part of it but I'm thinking changing the O2 sensors will help increase the mileage. Thoughts? Thanks gents.

 

[Anime]

The Mazda B4000 is the Ford Ranger with a 4.0L V6, just with slight cosmetic differences to "Mazda-fy" it, same as the Mazda B2300 is a Ford Ranger with a 2.3L 4 banger, too.

There should be two o2 sensors, one on each part of the Y-pipe immediately after the exhaust manifolds on each side.

They do affect gas mileage, but things like spark plugs, air filter, fuel filter, MAF sensor, and lots of other maintenance items and little things add up and can affect mileage, too. Having the proper air pressure in the tires helps, too.

 

[RangerX]

What's the pitiful mileage it's getting?

 

[dbailey]

Thanks guys for the input/suggestions. I'll change the O2 sensors for sure. Not kicking a light or anything but it can't hurt. So the 2 sensors mentioned would be upstream correct? Is there a downstream one? Will also check the other things mentioned as well. I'd say the pitiful gas mileage is around 15-16 mpg. I'll have to ask him to calc it again. Just remember hearing him mention that number once.

 

[awood]

They're both upstream. No O2 sensor downstream of the cat, at least on mine.

 

[dbailey]

Thanks a lot. I'll check to see if they are both the same or if 1 has a longer cable or something that makes you buy different part numbers.

 

[Anime]

15-16 mpg is normal for city driving for an 4.0L OHV V6 automatic, especially if it's got any mods like larger tires, though a pickup would likely get better mileage than a heavier SUV, depending on how it's equipped.

 

[dbailey]

Didn't realize that but I could be estimating on the high side. Will find out. No mods. Just a stock 4x4 4.0. 5-speed.

 

[Anime]

Well a 5-speed should get 1-2 MPG better than an automatic, depending on gearing, but that's still just 17-18 MPG in the city. Highway mileage tops out around 21-25 MPG.

Of course the actual mileage is usually less, depending how you drive, and how long the vehicle is idle, how many times it's started, things like that.

 

[awood]

I've never gotten better than 20 mpg with any of my 4.0's. But usually on the highway I was loaded down too. When my kids drive to school (less than 3 miles) both my 92 (RIP) and my 94 get about 12 mpg. I'm guessing that the EEC is just getting into closed loop mode by the time they get to school.