NEED HELP! System fuel too lean..P0171 error code!

Okay, I found this forum for 6th gen honda accords..The reason that i'm posting this is because i have a little problem with my honda accord..I already took it to two mechanics and they are not able to identify the problem. My engine light comes and goes off..and it gives the error code P0171 System fuel too lean. One mechanic said that it might be the MAP Sensor the other mechanic said that it might be the fuel pump. To be honest i think its cheaper to buy the MAP sensor than to install the fuel pump. Both of the mechanics checked for any leaks...Background history: A month ago my upper radiator hose blew off(Exploded) i replaced the hose and then i started to get car problems.(CAR WAS RUNNING FINE BEFORE THIS HAPPEN) The car is hesitating and it wouldn't accelerate properly, its kind of jumpy. Sometimes the car just runns in the mid 40's no more and i had to press the pedal down until reacted and then accelerate. Have somebody out there had this problem before? ANY HELP WOULD BE APPRECIATED? Now, question? What should I do first replace the MAP sensor or fuel pump? Any other ideas would be appreciated. F.Y.I. My car is stock..has 2 month old spark plugs, used distributor, new fuel pump, new radiator, new radiators hoses, like a year old O2 sensors in bank 1 and bank 2, new engine coolant temperature sensor..tats about it..wanted to give some more details.....This is a honda accord lx 4 cylinders...

quick google search, i got this

* In the vast majority of cases, simply cleaning the MAF sensor does the trick. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling
* Inspect all vacuum and PCV hoses, replace if necessary
* Check for a dirty fuel filter and proper fuel pressure

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thanks for posting...i alraedy look it up...also, but i also found out that cleaning it will not do the trick the best thing is to repalce it..But i'm going to check it out tomorrow morning..i know the mechanics checked the hoses, i don't think i have a vacuum leaked...the only thing that i have a doubt is the fuel pump and the MAP sensor..i'm leaning more into the map sensor because it got wet when the radiator hose blew up, plus it was boiling/hot water....i will keep this thread updated though....thanks..

JediYuhdigg said:

quick google search, i got this

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Our cars don't have MAF sensors.

Search this site for p0171.

http://www.6thgenaccord.com/forums/showthread.php?t=27791&highlight=P0171

http://www.6thgenaccord.com/forums/showthread.php?t=25899&highlight=P0171

sodaks2k said:

Our cars don't have MAF sensors.

Search this site for p0171.

http://www.6thgenaccord.com/forums/showthread.php?t=27791&highlight=P0171

http://www.6thgenaccord.com/forums/showthread.php?t=25899&highlight=P0171

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i was just about to correct him. but yeah if you map was bad, it would throw a code saying "blah blah map map map blah." so it has to be something that is not directly monitored.

-check your fuel pressure at the fuel rail.

edit- you can also have some debris (partially) blocking the fuel pump. just pull the pump out, clean it up and throw it back in.

Have a read at my threads...i had the same issue happen
http://www.6thgenaccord.com/forums/showthread.php?t=23814
http://www.6thgenaccord.com/forums/showthread.php?t=24598
http://www.6thgenaccord.com/forums/showthread.php?t=25899

However look at this first

DTC P0171: Fuel System Too Lean

NOTE: If some of the DTCs listed below are stored at the same time as DTC P0171 and/or P0172, troubleshoot those DTCs first, then recheck for P0171 and/or P0172.

P0106, P0107, P0108, P1128, P1129: MAP Sensor
P0135: Primary HO2S (Sensor 1) Heater
P0137, P0138: Secondary HO2S (Sensor 2)
P0141: Secondary HO2S (Sensor 2) Heater
P0401: EGR Flow Insufficient
P1259: VTEC System
P1491: EGR valve Lift Insufficient
P1498: EGR valve Lift sensor High voltage

1 Check the fuel pressure. Is fuel pressure OK? YES-Go to step 2. NO-Check these items: If the pressure is too high. Check the fuel pressure regulator, and the fuel return pipe. If the pressure is too low. Check the fuel pump, the fuel feed pipe, the fuel filter, and the fuel pressure regulator.
2 Start the engine. Hold the engine at 3,000 rpm with no load (in Park or neutral) until the radiator fan comes on.
3 Check the Primary HO2S (Sensor 1) output with the scan tool. Does it stay at less than 0.3 V or more than 0.6 V ? YES-Replace the Primary HO2S (Sensor 1). NO-Go to step 4.
4 With a vacuum pump, apply vacuum to the EVAP purge control solenoid valve from the intake manifold side. Does it hold vacuum? YES-Check the valve clearances and adjust if necessary. If the valve clearances are OK, replace the fuel injectors. NO-Replace the EVAP purge control solenoid valve.

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Well, I already ordered the MAP sensor from ebay, Denso brand..I'm going to replace it when i get it. I read most of the threads and some of them indicate the Fuel Pressure Regulator. I do not have the tools to check the pressure of the fuel and some other things. Right now i'm thinking of the MAP sensor doesn't fix it i will take it to pepboys or just tell my mechanic to change the FPR and check the lines for cloggs. Thanks for all the info.. i will keep updating this thread...as i fix the problem..thanks..

com520 said:

Well, I already ordered the MAP sensor from ebay, Denso brand..I'm going to replace it when i get it. I read most of the threads and some of them indicate the Fuel Pressure Regulator. I do not have the tools to check the pressure of the fuel and some other things. Right now i'm thinking of the MPA sensor doesn't fix it i will take it to O'reilly or just tell my mechanic to change the FPR and check the lines for cloggs. Thanks for all the info.. i will keep updating this thread...as i fix the problem..thanks..

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You shouldve just gotten it checked out then ordering parts for it already. Hope it works nonetheless

Okay, i replaced the MAP Sensor yesterday, i drove the car about 2-3 hrs, and it felt better, it wasn't hesitating, there was power..it wasn't jumpy..it felt good..but you never know Next week i might get the engine light again..what i'm going to do know is replaced the Fuel Pressure Regulator...and I guess if the light shows up again, then i have a fuel pump problem and thats were i'm going to take it to pepboys/mechanic..so i don't waste any more money ama let them figure it out now...lol...I will still update this thread if the light shows up again..thanks for ya'll help..Eventhough this is a 99 and replacing a sensor that hasn't been replaced for a while is a plus plus...

com520 said:

Okay, i replaced the MAP Sensor yesterday, i drove the car about 2/3 hrs, and it felt better, it was hesitating, there was power..it wasn't jumping..it felt good..but you never know Next week i might get the engine light again..what i'm going to do know is replaced the Fuel Pressure Regulator...and I guess if the light shows up again, then i have a fuel pump problem and thats were i'm going to take it to pepboys/mechanic..I will still update this thread if the light shows up again..thanks for ya'll help..

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Did you check your o2 sensor voltage readings or you just gonna replace everything in between one by one lol ???