had a check light throwing code 21 so i bought a new o2 sensor today, check out my old one haha.



truck was sluggish and seemed lean and gas mpg was TERRIBLE
Needless to say, the truck runs awsome now.

 

WOW! What kind of rig was this on? Maybe I should replace mine....Hmmm

 

did you do the seafoam? where is taht sensor located?

 

check your cat convertor. if the sensor was throwing your system rich your cat's life will have been shortened or killed

 

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i just put on a flowmaster 40 serioes so i took the cat out of my system all together at the same time, and it was on my 1989 toyota pickup 3vze.

sensor was in the exhaust right before where my cat used to be.

What is seafoam, never heard of it...???


also, as soon as i replaced it, the check light went off, so i should be good to go, performance gains were very unpredictable, runs way better than i could ever have imagined.

 

seafoam is an engine cleaner it is the best , what kinda yota was that 02 sen. on i have a 95 4runner please PM me with what kinda yota that o2 was on and what brand of 02 your just bought?

 

How hard was it to take off the exhaust pipe and what method did you use?

 

it simply unbolts with 14mm bolts/nuts

 

yeah its only held on by 3 14mm bolts, i should prob check out my o2 sensor truck running like and horrible gas mileage. I pulled off the whole exaust system when i did my clutch a few months ago and saw that the bolts holding on the O2 sensors is hella corroded on. So seafoam is suppose to help get it off easier?

 

no seafoam is like a fuel injector cleaner/engine cleaner and etc...not much will make the bolts easier to get off except for a wire brush and some heat, and maybe some penetrant

 

mine only had two nuts holding it on, but i used vicegrips to get them off becasue mine were wasted. Also used a lot of PB blast. Just replaced the nuts afterward.

ill post mileage boosts in about a week or two because im currently painting my truck so wont be driving this week

 

Mine looked like that before the cat on my 94 at 110k. Scarey stuff lol

 

*thread jack*

Need to replace my o2 sensor and the bolts, they are completly rounded off.
Anybody know what size/thread type they are so I can go to the hardware store and get some new ones?

 

https://www.yotatech.com/forums/f2/02-sensor-qs-65796/
https://www.yotatech.com/forums/f2/o...ut-bolt-16010/

a good suggestion if yours is the stud with the nut, then its best to try and get that off with some penetrant soaking. If you break that stud, things will suck. A good option is to use your dremel and cut through the nut to break the nut off. also wire brush it to help.