Looking for alittle help. Went to Autozone and had them scan my 1999 F150 5.4 with 88,000 miles on it because of a check engine light that keeps coming on. They told me the codes were

po153 o2 sensor slow response
po171 Bank 1 running lean

Can anyone tell me what I need to try to get these codes to clear? I have tried to disconnect the battery and clear the codes, but they only come right back on after alittle driving. Also can someone direct me to a diagram that shows the position of all the sensors, maf, coils, PCV, and such under the hood. I see some individuals taking about them but have no idea what or where they are located. Any and all help greatly appreciated. Thanks

 

The P0153 is for the 02 sensor on the drivers side. Sounds like it's life has expired. It could trigger the P0171 for the other side due to the fact that the pcm is trying to compensate for the slow 02 response. Replace the 02 sensor, clear the code and see if the other code comes back. But it shouldn't.

 

Should I use the Ford O2 sensor or is there a better one available from the aftermarket side of the automotive industry. Do I replace the sensor before or after the cat converter?? I have 4 O2 sensors and the ones before and after are different part #'s at the dealer.

 

Actually you only have 2 02 sensors. The rear 2 are actually cat monitors. They monitor the cat converter efficiency. The 02 sensors actually monitor the gas and air mixture. The one yours is coding for is the front one on the driver's side. You can use which ever sensors you prefer. I personally prefer the Ford ones, but that could be cause I work there and I get them cheap.

 

The Ford ones are quite pricey, use Bosch brand, as they make them for Ford. Pep boys has them at around $50 each. Since you have 88k miles, go ahead and replace both upstream sensors.

 

Don't forget to keep the good one for a spare.....Just in case. You never know what can happen..

 

Had same problem and went ahead and replaced both front two. You will notice better mpg. Real easy to change. 30 minutes for both. Good luck.

 

Well since you put it that way, I think I will change both upstream O2 sensors. The Ford one cost $103.00 here. We have a Pep boys not too far from me I can go get the Bosch ones at. Thanks for the tip.

Is there anything else that I can do to clean out the intake/ throttle body, etc before I change to the new O2 sensors. On the old carburated engines we could pour water down the carb and clean the carbon from the heads/pistons/valves. Might as well do what ever I can to help my truck last a longer before I put the new parts in.

 

Read up on Seafoam. Lot of good threads on it.

 

Had my fuel filter replaced yesterday. Also while my mechanic was doing that he checked and reset my codes. At that time I was showing lean on both banks and O2 sensor slow response on both banks. The filter was completley plugged. He reset the codes and so far with 60 miles on the new filter everything is OK.
While he was under the hood. We replaced the PCV valve and found that the problematic header tubing to and from the PCV valve was in bad shape. We patched it for now but I will probably end up replacing the complete header setup because the rubber is very gummy feeling.
Will keep you posted but for now all is well.

 

sounds good, yeah those pcv give alot of problems. I changed my fuel filter yesterday and it was completely clogged after 20,000 miles. Good luck and hopes that light stays off. I'm ordering a superchip next week and I hope it somehow mysteriously fixes my rough idle. i saw the post you started about 4 years ago on the same problem. Ive cleaned and changed about everything you can think and still nothing. Im not gonna quit though.

 

Good luck with the rough idle. I have given up on that issue. Now I'm just trying to maintain my truck so I can get all the years out of it that I can. Other than the rough idle issues I've had a pretty good truck maintenance wise.

 

Well I made 290 miles before my check engine light came back on again. This time it only coded slow o2 sensor response. Since I bought the O2 sensors already I will change them out tomorrow when the exhaust is cool and see what happens.