Hey everyone I just joined yesterday and ive been looking for posts of a similar nature and havent had any luck; this bogging and stench (kinda like rotten eggs) only occurs in 5th gear between said RPMs and 60mph and up.Never between 1st thru fourth. The check engine light only comes on during freeway travel also so i pulled the code and was 5 blinks= O2 sensor or circuit So i replaced the O2 sensor cleared the code and Every thing seemed cool till i got on the freeway again check engine code says O2 and the symptoms have seemed to gotten more frequent and stinky....Any help will be appretiated .Thanks

 

What brand 02 sensor did you get ?, if you got a Denso 02 sensor then that`s the right one, if you got a Bosch 02 sensor then that might be the problem, most toyota`s don`t like Bosch 02 sensors. It would also be a good idea to replace the fuel filter and give it a complete tune up. Also pull the throttle body and clean it. What about the exhaust, is it all stock ?, is the cat the original one ?. Any other mods to your 4Runner ?.

 

Ill try the tps cleaning i changed the filter yes, and the exhaust is all stock, i thought about the catylytic but it looks new , I know looks can be decieving though and thats a big money part as is the fuel pump which im going to look at tomorrow , but dont really see anywhere to check pump pressure.

 

replaced the AFM too oh and yeah unfortunately i got the bosch O2 sensor

 

I would highly recommend that you get a Denso 02 sensor and remove that bosch 02 sensor. There have been many people here that have had problems with bosch 02 sensors, they just don`t work well in toyota`s. Just to be clear, DON`T clean the tps, clean the throttle body and be careful not to get the cleaner in the tps, it can ruin it.