Hey ya'll I'm new here. My 99 2wd 4Runner with the v-6 is showing P0303 code (cylinder 3 misfire) and P0171 (System lean bank 1). I have put new borg-warner wires and NGK dual electrode plugs in it and still get the message. Sometimes under hard acceleration the "check engine" light blinks on and off (which I was told was misfire). Doesn't sound like it's missing and haven't noticed any obvious drivability issues. My next thought is to swap the coil pack off number 3 and see if the miss moves with it. Any other ideas?

 

P0303 - is probably a coil pack but you need to test it before replacing
P0171 - is often the MAF sensor needing cleaning but can be due to other factors too

 

You're two for two! I swapped the coil pack to #1 and read the code, the code moved to #1, I moved it to #5 and it followed so I replaced the coil pack. After searching here, I cleaned the MAF sensor and cleared the other code.

Now to solve the other issues with this truck.

 

I don't bat 1000 very often but glad I could help.