I know, I searched before I posted this but I'm posting anyway. I took my truck to get it inspected today and as I was leaving (after I passed) my check engine light came on. I took it back and they said they had nothing to do with it. Anyway, I had them check to see what it was and code 25 came up. So it's running lean. I've got 160k miles on it and I'm pretty sure it's the original 02 sensor so I figured I'd try to change it. When I was on the way to Toyota to get one my light went off and has stayed off. I get around 13.5 mpg around town with an auto so an O2 could be the solution. But right now there's no light so should I leave it alone? Or is there still a problem and the light shuts off intermittently? Any opinions on this will be appreciated.

 

Not sure if codes same for yours but 25 on mine says 02 sensor or fuel malfuntion, so definately is pointing to those two.

sparkplugs.com have a reasonable price depending on if you want plug and play or save some money and get universal DENSO's where you have to reuse your old plug or rewire. Check their prices, you got time to order one. Will most likely help gas milage also.

 

Thanks, I'll check it right now

 

sparkplugs.com, sorry! Does yours have two? You may have to go by the FSM and test each one to narrow down. Also I think the page redirects you to densoproducts.com.

 

From what I can tell there is just one, right before the cat. I'm having a hard time with the fact that the CEL came on and then a few hours later went off. Any ideas why it came on then cleared itself? Either way I guess I'll throw an 02 sensor at it. According to my manual it could be about 8 different things.

 

I have seen them come and go like that or at least mine did. There is a test in the FSM for the o2 sensor and that's how I determined it was bad.

The manual is generic about looking at possible problems and each thing it suggests could be the problem as the ECM doesn't have enough memory to specifically narrow down the cause. The later ECM's were better at narrowing down problems, but still may list more than one problem area. Reason I say test the o2 sensor, but in my opinion the o2 sensors should be replaced every 100K. I think the Cat converter should also, but that's my opinion. I know people have gone double and triple that number, but they do lose their efficiency and can get clogged.