We have a 2003 Explorer, V8. Recently the service engine soon light came on,and had it scanned today. We received these three codes, 1151, 0171, 0174. Guy at autozone basically said it means the engine is running lean. I have seen the p1151 code on other threads, but nothing in relations to the others. Any help?
Or am I just missing the right posts to help with this.

Thanks

 

My 1997 4.0L ohv engine had the P0171,P0174 codes for quite some time....as well as overheating issues. My son drives this vehicle and it's due for a smog check for reg renewal....and he needs a reliable car.

The lean condition was from leaking upper intake manifold gaskets creating a vacuum leak and a lean-out condition. The drivers side head was also seeping coolant. I put Bars Stop Leak in a few years ago and that just seemed to clog the water jackets.

This last weekend my son and I did a marathon Sat/Sun tear down and replaced the upper and lower intake manifold gaskets, head gaskets, exhaust manifold agaskets, EGR valve gasket, throttle body gasket, and replaced the spark plugs. Cleaned the heads, manifolds, throttle body.

We numbered each electrical connection for easy reassembly. Very careful to not break any connectors....the mileage is at 156,000...I bought it new and have taken good care of it with regular oil changes. the crosshatch pattern was still visible in the cylinder walls. Mobil 1 is good!! Cam was good....valves good....combustion chambers a nice beige.

Our aim was to get it back to running clean and strong and not fix what wasn't broken...and to pass smog check.

We fired it right up after reassembly and oil pressurization from disconnecting the coil pack from the harness.

Cost of the job was about $325 and 19 hours. We didn't hurry and did meticulous work. Saved about $900 by doing it ourselves.

Codes are gone....runs great....doesn't over heat...and my 16 year old son and I had a great bonding weekend.

 

There is a possible cause for those codes in your 4.6l and solution discussed in this thread at another forum:
Rough idle and "Check vroom vroom Soon" light - FIXED - Ford Explorer Ranger Enthusiasts Serious Explorations
The vroom vroom in the title is part of a silly April Fools gag someone pulled over there. I have had this bookmarked for a while now since the poster over there has the same model and build date as my Explorer. Please let us know if this turns out to be the problem with your '03.

 

duplicate post, see below.....

 

Had same "lean right bank" codes on 1999 EB V8 5.0 AWD. Also had pinging under load condition show up.

Traced cause back to to dirty MAF sensor, caused by oil/dirt particulate buildup on the thin wire in the MAF sensor. The oil was coming off a K&N air filter installed new 10K miles ago. The oil buildup on the thin sensor wire in the MAF sensor was causing the sensor to report incorrect airflow volume to the computer, which then was adjusting the air/fuel mixture and resulted in it being too lean.

To fix, remove the MAF sensor housing from the air filter box and rubber intake. Go to Radio Shack and purchase a can of their aerosol electronic parts and circuit board cleaner. DO NOT use engine/parts/carberatour cleaner as these generally leave a residue. Spray cleaner into MAF sensor to clean thin wire. DO NOT use rag or any tool to clean wire as will likely break it, requiring purchase of new MAF sensor. Repeat cleaning of thin wire till all accumulated dirt/oil is gone, then allow to dry. Reassemble, reset codes and test drive.

After performing this service and replacing K&N filter with FRAM High Mileage filter, have had no further problems or codes. Also, pinging is gone and performance has returned to previous levels. Just passed 250K in mileage and headed towards 300K now.

Good Luck!

 

Thanks for the link rrgone. Found the hose and it was compressed with a tear. Autozone and Nurrays didn't have anything asreplacment, so off to the dealer I go. Hopefully this is the only cause. Thanks again.