Hey guys I have a 1999 f150 with dual exhaust. The codes show that I have 2 bad o2 sensors but I don't know which is which. The codes say sensor 1 bank 1 and sensor 1 bank 2. I was told they should both be on one pipe but I don't know which.

 

What are the exact numerical codes, please? I'm betting your sensors are fine and you have a related issue.

 

Bank 2 sensor 1 should be driver side before cat. Bank 2 sensor 2 is after cat. Bank 1 sensor 1 is before cat on passenger side and bank 1 sensor 2 is after cat on passenger side. If going from the top and it's tough to get off with a wrench, buy a crowd foot, use your ratchet wrench with a cheater bar. More to than 12in wrench will give you. You don't need dealership to fix lean or rich mode as the ecm controls that. You have a bad sensor which is causing your truck to rich or lean out, it's not the factory tune giving you the cel.

 

NOT necessarily true - rich or lean is almost never caused by bad sensors, they are REPORTING the excessive lean or rich condition. This is why I asked for the exact codes!

 

Spent $2000 on my old altima when the afr (bank 1sensor 1) went out. I replaced the egr and secondary 02 sensors along with the cat because of the cat pipe rusting.

 

We are throwing darts without the exact codes. Would be nice if the poster would say something - it's been 18 days with no response.

 

That be true glc....