Intermitent Rough Idle

[emadrid37]

I have a 2000 Toyota Sienna LE van with approx. 177k miles.
Problem started with engine light coming on with codes P1130 and P1135 which are air/fuel sensor codes. It was bank 1 sensor 1 which is located at the firewall. Engine would idle really rough only when it was nice and hot with the a/c on. I replaced the sensor and soon after the engine light came on again. Had several codes which were P1150 for bank 1 sensor 2 located behind catalytic converter, P300 for multiple cylinder missfire, P0304 for cylinder 4 missfire, and P0306 for cylinder 6 missfire . I replaced that sensor. Engine light came on again and the intermitent rough idle started again. I replaced the last sensor for bank 2 sensor 1 which is located behind the radiator at the front of the engine. I had the engine light reset and codes cleared. Van is running great now with no engine light or rough idle. I wish I would have just replaced all three fuel/air sensors at the same time. This would have saved me a lot of stress. I was told that the sensors usually only last up to 100k miles. These sensors send the signals to the computer telling it how much fuel and air are needed. I hope this post helps someone else in the future.

[SiennaCruza]

You use a cheap mom & pop gas or your plugs or any of the ignition system components are bad and those air/fuel sensors usually go bad prematurely. Heck I've had to replace the bank 2 sensor twice at just under 100k. Now I don't risk it because of gas prices I usually look for the best price. NGK IX Iridiums are the best way to protect your sensors because they are of the best spark. I'm not saying 87 gas @ boonies gas station is the best way to go but if you must also consider an additive to help with such cheap untreated (no detergent) gas.