az dakota

Hello! I have an f150 with a 4.6 motor. Bank 1 precat o2 sensor has been bad for 3 or more years and it has run fine
. Lately, it runs great until it warms up, then it has no power and idles rough. If the o2 sensor hasn't bothered it for 3years, why would it bother it now? And no, bad o2 did not affect fuel mileage. All responses are helpful.

wilson84

Proly something else and my other codes

wilson84

Proly something else any other codes

Frank_Ford

Most of the time when the O2 sensor code comes on it is something that is causing it to come on and not the O2 sensor itself. I would start by looking at your MAF sensor and cleaning it. This is low cost maintenance and can make a huge difference in the running of your engine. Also look at the air filter and change it if it is dirty. see if you have any other codes as you could have a vacuum leak or a stuck EGR valve.

az dakota

First off, thanks for all the responses! I have cleaned the MAF but symtoms remain. Stupid me, I have yet to check the EGR! Thanks for the reminder! Air filter is 1 month old. Only codes are for O2 sensor.

Carcrazygts2

THere was actually a TSB about the A/C drain dripping on the bank 1 sensor 1 o2. It can cause misfire concern as the oxygen sensor shorts and wreaks havooc on the PCM. I experienced this issue and it caused a failure in the PCM.

az dakota

Thanks for the TSB info!

Jbrew

3 years! Well, that's one way to run it into the ground

But hey, -if you don't care... - why should anyone.....now?

Geezzzz

az dakota

FYI, I do not own the truck. The owner ignores the CEL and only brings it to me when it develops issues like this. He believes the CEL is the manufactures way of making more money from people.

02_Black_On_White

lol