Fellas
I changed the two front O2 sensors and now I find my milage is down by 10-15% . I did get 650-700 Ks to a tanks so about 13.4 lts/100. Now I only get 500 Ks+ so 18.8lts/100. Any thoughts? I know when I changed my wifes in her old Explorer. It helped.

 

What year truck, motor and brand O2 sensors?

 

Motor craft sensors can be had at Rock Auto for less then 50 bucks each. What kind did you use?

 

Its a 2000 5.4, 4X4 Flareside, I used NTK 22500 sensors. It has 212K. They are the same ones for my wifes Explorer. And were purchased at the Ford dealership for half of the Motorcraft ones.

 

I believe some factory 02's were bosch. Which can be had for about $40

Did you disconnect the battery for the change?

 

Motorcraft sensors are $38.79 at rock auto. That cheap and using any thing else is just dumb. Obviously the ones your using arent up to the task.

 

i ordered stuff from Rockauto and it cost me more than what I would pay here in canada. ive used them in my other vehicles with no problem but maybe the truck does not like them.

 

Agreed. But bosch were the factory 02's in a lot of models. I removed Bosch 02's on an 01 with only 10k miles. They were factory installed. So, if you don't want to order online and can only find bosch at local auto supplies and the dealer wants to charge $85 per motorcraft... I would assume pick them up if the price difference is only a few bucks and you need them asap.

OP, like stated from others, the ntk's are probably the issue.

 

I dont know about that, Bosch being OEM. Rock Auto lists NTK as being the OEM supplier. Its like Autolite plugs though no mater what. Motorcraft parts are manufactured to OEM specifications any thing else who knows. I saw a post once where someone used Bosh and then Motor craft and the trucks economy was better with the Motorcraft. I have Bosch in my truck bought them before I found Rock Auto my next set will be Motorcraft.

 

I have motorcraft in mine. I'm not disagreeing that the motorcrafts may be a little on the better side function wise. If I remember correctly, there were some tests done on efficiency with the bosch vs motorcraft. The motorcrafts were more stable. But I'm confident they came with bosch from the factory. The sensors I removed from the 00 during my swap had the ford logo on them and were Bosch. I believe some of the NTK's have the ford logo though as well. Now that I looked back on an old post, from the factory the upstreams were NTK with a ford logo and the lowers were bosch with a ford logo and I beleive share the same part number as the "motorcraft".

Either way, go with motorcraft for the best efficiency.

 

Ill look at the old ones. In my wifes truck it had bosch and ntk stamped on them we own the truck since new. I get the goverment discount at ford. The parts guy is a friend and told me that they install ntks if mcs are not instock ill go and buy a set of mcs next week. And try them like I said maybe the truck doesn't like them. My old aero hated anything but mcs plugs

 

Thanks fellas will keep u up to date

 

Give it a shot. Also, not sure if anyone asked but was there a reason you changed the upstreams?

Again, make sure you disconnect the batter to reset the pcm

 

I have 212k on the truck and they have never been changed. Which I was told they were, but dont look like it. I reset using my scan tool. So I though it was time to change them. Just to add I did have the bat disconnected.

 

Question... How often should you change your O2 sensors? As far as I know mine are original with 149xxx miles on them....