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Discussion Starter · #1 ·
ok about 5 months ago i had to get my car smog checked because i moved to cali. my car failed horribly because the o2 sensor was burned up and it had not thrown a code yet. anyway, ford replaced it yada, yada, yada.
well now my car is producing the same exhaust smell as it did when the o2 went bad and i think the milage might be dropping a bit. i'm pretty sure the dealership will replace it again but i'd like to know what's causing this.

my engine mods-
cam gears
street header
hi-flow cat
tb
flex-pipe
catback
diablo chip
udp
intake
 

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Ford has issues with the upstream / heat O2 sensors. They burn out fast. You have a number of modifications like the header, high flow cat, chip that will deffinetely burn the sensor "higher temps".

I had the same issue and I changed the upstream sensor. These are not made for above normal engine temps.

George
 

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Discussion Starter · #3 ·
what did you change it to? i plan on replacing the shorty/hi flow combo with the FS 4-2-1 header when it comes out. will this change anything? i think i read somewhere on here that the shorty headers generate more underhood heat than the race headers. of course that could be complete B.S.
 

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Ford has coded each O2 sensor depending on the type of vehicle or CARB regulations for each state or region. So according to Ford there is a code in the door of each car that gives you the O2 sensor codes.

I did not have such sticker so I had to remove the upstream O2 which by the way was melted and welded into my highflow cat and read the code from it. The upstream O2 goes for $95 dollars and 90% of the time this is the one that goes.

I tried a unviversal one to see if it would work and save money, just to confirm that Ford was right and I ended putting out the $95 after all.

All issues were fixed ever since but it was expensive. I had to weld a new fitting on my high flow cat to make this thing work.

Headers in general will be hotter than your standard exhaust manifold.

George
 

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Discussion Starter · #5 ·
Headers in general will be hotter than your standard exhaust manifold.

George
damnit, i was hoping you wouldn't say that. i guess i'll just have to resign my self to replacing the o2 sensor every 5 months. oh well, i'll be taking the car to the dealer in a week or two and hope they do it for free. if not at least i have a reason to open the great big box of rarely used tools.
 
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