i went to advance auto today and hooked up their computer and i have a malfunction heat o2 sensor it says its the one on the down pipe... how hard is that one to get to and to change ? it threw p0141 at me it says " o2 sensor heater circuit malfunction bank 1 sensor 2" anyone know how serious this is.. i plan on fixing it in about 3 or 4 months when i get new tires and brakes. also i had the hood popped up and after the engine shuts off i hear a hissing noise... i read on google it maybe a vacuum leak ? hows that related to a o2 sensor

 

O2 sensor is easy to change. One plug, then screw it out.

Kurt

 

i know that Ive done several before but Ive read a lot on the internet that it did not fix the check engine light. and i was wondering about that hissing noise i hear after shutting it off...

 

Some vehicles has up to 4 oxygen sensors. So if someone replaced the wrong one, then no the light won't go out..
it won't damage anything. It may or may not effect your gas milage. If it does, it won't be much.
Does sound like you have a vacuume leak to me. (By your discription)
check all your little hoses for cracks. See if you can locate where it is coming from. Good luck.

 

wouldn't that vacuum leak pop up in my codes ? idk how i would find the leak seeming there's like no room to see... idk how serious a vacuum leak is or can get to be over time ?

 

After you change the o2 sensor, you have to disconnect the battery to reset the computer.

Kurt

 

ok so you think that hissing noise after i turn it off is the a/c compressor adjusting pressure ? not a vacuum leak

 

If it were me, i'd deal with the o2 sensor.

give it some time to see if the hissing noise continues.

with the way the weather has been changing from cold to nice and then back to cold, it may be having a effect. If it is a leak, then it may be easier to detect later as it gets worse.

 

my dad is pretty sure its the a/c making that noise... and does mercron automatic transmission fluid sound right for power steering fluid ? guy at advance looked it up and that's what it called for so i was trusting them for once...

 

About a week ago i had the same problem. had "heated o2 sensor circuit malfunction" I replaced one of mine and happened to be lucky. It was the malfunctioning one. But my truck has 4, yours prolly does too.