freekin fords, i just had to use my "pulley" money to buy 4 o2 sensors for my 99 .........if that aint enought to make a guy mad, i dont know what would. approx. 50 bucks each. made by Bosch.but they come with a lifetime warranty.meaning the sensors will be around longer than the freekin truck will..what gives.........ahh well i just have to suck it up and install the lil b"stards.....maybe it will help my truck from poor idle , gas mileage and hesitation. shoot for the price it better, sorry just had to rant........time for a beer

 

and reset your computer....they are the ones that take the abuse...besides what makes you think that it,s the sensors...are you pulling a code?

 

I just have to replace the first 2 sensors? what exactly do the last 2 do?

 

that the cats are working to spec

 

yea got the codes pulled from Auto Zone......... the guy told me it was the o2 sensors.......... plus i have a "SES" service engine soon light, ahh....... i have all 4 so im gonna change them all .......... done paid for them might as well do it.......

 

so then its safe to say you can just replace the first 2 sensors and not have to do the rear?

 

Another story of the AutoZone kill.

I am begining to think they stay in business based upon the fact of how many O2 sensors they sell each year.

Don't ever believe the AutoZone tech.
They usually take the 5 word description which states the reporting device and tell you it is bad.
The list of what to look at in the Ford service manual is much longer then just the reporting device of the error.

There are about 12 different error codes that the O2 sensor can report on. These range from maybe a faulty O2 sensor, to something as simple as the oil is overfull, the dipstick is not fully seated, the MAFS connection is loose / off, or even the typical cause a vac line is disconnected or cracked.

Post the code, and myself or another can take the excerpt from the Ford service manual and provide you with the list of things to check.

Just trying to save your pulley money.

 

HI!... WOW! $50.00(U.S) each! What a deal! Here in CANADA, my dealer wanted over $200.00(CAN) each. But recently FORD has been doing some price reducing on many of their parts and the price has dropped to $133.00(CAN) each. At $0.60 for the exchange rate between money's, the american price would only be $320.00(CAN), compared to $532.00(CAN) plus 15% taxes would equal $612.00(CAN). So count yourself lucky that you got them at a good price. By the way the factory O2's are made by BOSCH as well.

 

I remember when I went to pepboys for O2 sensors they only listed 3 of them. They had 3 different part numbers. I was wondering why they didn't list a fourth. But for the 3 sensors it would have been around $175.

 

I had a SES and had autozone pull the code and it was right bank lean and of course they wanted to sell me an o2 sensor.

I cleaned my maf and reset the computer and no more problems, heh.

Take the two downstream o2's back for a refund at a minimum.

WYOMING - I noticed you have a K&N. My K&N was what set the SES off and fouled my MAF.

 

OK .........i guess i did not tell the whole story here.........the SES light came on at Exactly 60,000 miles. ........ so i figured it was the dredded 60 grand "check-up. more money to give to the dealer. so now my 99 has just turned 63 grand and the SES light is still glowing like a child on X-mas morn........... i have had the truck for about 6 or so months and have put about 20 grand on the odometer since then. with no problems to speak of. so at around 58 grand the engine desides it wants to hesitate under hard acceleration and it will idle real......... i mean way low....down to almost 4-500 rpm's........enought to make it wanna die. Also it will Die on me if i turn into a parking spot or turn onto another street. so solution....add power steering fluid,...topped off that tank....still no fix....changed plug wires about a month ago at a cost of about 100 bucks....looks great ............Motorsport Blue's under the hood.......... but thats all they are for...........looks.....still no fix..........so i figure i would go to my "trusted" shadetree mechanic's "wal-mart" ie: AutoZone........and well ya'll know the rest of the story.......Some One please help me......for my Mighty F-150 is sick....Im in need of an F-150 GURU

 

reset the computer..then see what code it flashes...it could be your chip

 

i will try that thanx .......... lets hope that works..........at this point i will try anything.........

 

OK Went back to my local Auto Zone.........had the "kid" pull the codes again........Hey its FREE...my dealer wants 85 bucks to pull codes and a few hours.........what a crock of chit.......anyhow..........here is what is showed code # PO175 Banks 1 and 2 thats all it said.and he mentioned again O2 sensors........so i returned the downflow sensors to Advance Auto and got 100 bucks back.........so now i just need to change the Header sensors.........but please........who-ever mentioned cross-referencing the code number..........could you still do that for me..........thanx

 

Here you go :
DTC
P0175 - System to Rich (Bank 2).
Description
The Adaptive Fuel Strategy continuously monitors the fuel delivery hardware. The test fails when the adaptive fuel tables reach a lean calibrated limit.
Possible Causes
See Possible Causes for DTC P0171.
Diagnostic Aides
See Diagnostic Aides for DTC P0171

Sp on to P0171...
DTC
P0171 - System to Rich (Bank 1).
Description
The Adaptive Fuel Strategy continuously monitors the fuel delivery hardware. The test fails when the adaptive fuel tables reach a lean calibrated limit.
Possible Causes
For lean and rich DTCs
-Fuel system
-Excessive fuel Pressure
-Leaking /contaminated fuel injectors.
-Leaking fuel pressure regulator.
-Low fuel pressure or running out of Fuel
-Vapor recovery
Induction system:
-Air leaks after The MAF
-Vacuum Leaks.
-PCV system.
-Improperly seated engine oil dipstick.
EGR system:
-Leaking gasket.
-Stuck EGR valve.
-Leaking diaphragm or EVR.
Base Engine:
-Oil overfill.
-Cam timing.
-Cylinder compression.
-Exhaust leaks before or near the HO2Ss.

Did he give you the correct code or only the first code that came up, and he passed the second code ( if it is tossing 2 codes ).
This mentions nothing about the O2 sensor, the closest is leaks near the O2 sensors.
Good old AutoZone
Couple this with the problem you noted above, I would look at the MAFS to see if it is crapped up, and maybe you need to look at the fuel delivery next, these are all listed in the rich / lean section above. I just included the whole listing from the Ford Service manual.