2003 Sport Trac Lean codes

[Patrick Hunt]

As we've all come across those pesky lean codes, P0171 and P0174....I have seen different things to troubleshoot the problem from MAF sensor dirty, to PCV valve dirty to a vacuum leak in the elbow going to the PCV valve. Well, I did all the above, I cleaned the MAF, replaced dirty PCV valve and checked for the cracks in the elbows. Still no joy! So then, I thought what is making this come up lean....It's either too much air or not enough fuel....one or the other. So I went down to Harbor Freight and bought myself a fuel pressure gauge...about $20.00....Nice one too and I checked the pressure on the rail...Typically, it's supposed to have 55-65 psi at the rail....I had 35 psi....So, knowing the pressure regulator is in the tank with everything else...I bought me a new pump off Ebay. If you go to the major auto parts stores, plan on about $168-$175 bucks. Ebay had them for $72.00. I also would highly recommend you take the bed off....Makes getting at the rear strap bolt soooo much easier. After putting everything back together, and taking it on a test drive...My truck has much more get up and go and most importantly....No codes! There are some things I have learned that could make it easier for you if this is something you are going to have to do....Would be glad to advise for any issues.

Patrick

 

[koda2000]

As we've all come across those pesky lean codes, P0171 and P0174....I have seen different things to troubleshoot the problem from MAF sensor dirty, to PCV valve dirty to a vacuum leak in the elbow going to the PCV valve. Well, I did all the above, I cleaned the MAF, replaced dirty PCV valve and checked for the cracks in the elbows. Still no joy! So then, I thought what is making this come up lean....It's either too much air or not enough fuel....one or the other. So I went down to Harbor Freight and bought myself a fuel pressure gauge...about $20.00....Nice one too and I checked the pressure on the rail...Typically, it's supposed to have 55-65 psi at the rail....I had 35 psi....So, knowing the pressure regulator is in the tank with everything else...I bought me a new pump off Ebay. If you go to the major auto parts stores, plan on about $168-$175 bucks. Ebay had them for $72.00. I also would highly recommend you take the bed off....Makes getting at the rear strap bolt soooo much easier. After putting everything back together, and taking it on a test drive...My truck has much more get up and go and most importantly....No codes! There are some things I have learned that could make it easier for you if this is something you are going to have to do....Would be glad to advise for any issues.

Patrick

Good point. Low fuel pressure can also set the P0171/174 lean codes. Even a clogged fuel filter can lower the fuel pressure to the engine (and kill the fuel pump).

 

[LONO100]

my fuel pump failed on me a few months ago. luckily, i only had a few gallons in the tank, and it failed while it was in my driveway. if the tank is empty, i would really suggest not taking the bed off and just undoing the two straps that hold the tank to the undercarriage. if you put a jack underneath the tank to hold the weight of the tank as you undo the straps, its a piece of cake to drop the tank and replace the fuel pump. i would have had it done in under 2 hours if it wasnt for autozone giving me a fuel pump to a sport and not a sport trac.

 

[koda2000]

my fuel pump failed on me a few months ago. luckily, i only had a few gallons in the tank, and it failed while it was in my driveway. if the tank is empty, i would really suggest not taking the bed off and just undoing the two straps that hold the tank to the undercarriage. if you put a jack underneath the tank to hold the weight of the tank as you undo the straps, its a piece of cake to drop the tank and replace the fuel pump. i would have had it done in under 2 hours if it wasnt for autozone giving me a fuel pump to a sport and not a sport trac.

I totally agree with not taking the bed off and just dropping the tank. Did my ST's fuel pump last June. Quite easy to do.