My 98 sr5 4Runner with 5vzfe is running lean and I don't know what oxygen sensors to get. I did a search and I know I have seen pertinent threads but I cant seem to bring them up now.

I know the oxygen sensors are different for every year and even for the front and rear so I wanted to make sure I didn't drop $170 on the wrong ones.

One thing was weird, I sat using the internet at the library with the ac on and it overheated and started to steam a bit (new radiator and thermostat last summer so that's not it) and right after it felt great and was not running lean for maybe 80 miles, but now its bad again. Dunno if that is normal for bad sensors or if it tells you something.

The runner has 180k and the sensors are probably at least 60k and 5 years old or perhaps way older.

 

I just replaced my front O2 sensor after it failed. The first CEL code I received was for running to lean (cant remember the code #); however my MPG was continuing to decline. After I cleared the code, my truck ran for another couple of weeks before I received the P0131 code that would not clear. As others on here have suggested, I replaced my front sensor which is the more expensive of the 2. I purchased mine from sparkplugs.com for around $170 or so. If you still have questions of if its the front or the back sensor, get the part numbers of their website and punch it into the search on here to verify.

For me, after two months, no CEL and better MPG. Some of the guys on here note that once the front goes, the rear usually follows not too long after. So far so good for me. I also believe the Haynes manual says to replace these after 95k miles.

Good luck!

Chris

 

Thanks man I'll do that.

 

Theres no CEL but Cleaning the mas and checking for leaks in the intake yielded nothing. And I know they are old, but not how old.

Found a set on amazon for 149.28 shipped to me in two days.

 

If they are Denso, I believe they have different part numbers.