Please help!

hound9164 · Post by **hound9164** » Fri Jan 04, 2008 8:23 pm

I keep getting Cel P-0171, which is lean on bank one, keeps occuring

the causes are:

good trip equal to zero
restricted fuel supply line
fuel pump inlet strainer pluged
fuel pump modulator
o2 sensor
o2 signal circut
o2 return circut
o2 sensor heater operation
throttle postion sensor sweep
map sensor operation
etc sensor operation
engine operation problem
fuel contamination
exhaust leak

I figure that i have a leak in a line, or it is the O2 sensor. how much is a new sensor? also, what lines should i check? i know older cars, but not newer ones, so i could really use some help on this on guys!

Thanks in advance!

hound9164 · Post by **hound9164** » Sat Jan 05, 2008 12:16 am

only 4 views?

quicksilvr · Post by **quicksilvr** » Sat Jan 05, 2008 10:32 am

That's a tough one, because (like you listed) there are a ton of different causes. Probably the easiest thing to eliminate first is the O2 sensor...just get a new one, and check the wiring and the plug when you're changing it. A Bosch sensor is going to run over $100....but I haven't bought one for a while.

But then you've got the entire fuel system to check and eliminate, the TPS and the MAP sensor.

How long have you had the code? Have you filled the gas tank up with different gas yet? Can you hear an exhaust leak anywhere? How many miles on your car?

Best bet might be to take it to the stealership if you can't get it figured out....sucks I know.

hound9164 · Post by **hound9164** » Sat Jan 05, 2008 2:19 pm

I have had the code for 3 weeks. i have filled up with different gas, so its not the fuel contamination.

miliage is 38K

i dont think there is a leak in the exhaust system, cause it sounds just like it always has.

yeah, i figure i will have to take it in. that seriously blows.

Post by **jonnymopar** » Sat Jan 05, 2008 5:03 pm

A 2003 with 38k miles... aren't you under the 7/70 powertrain warranty still?? Funny to think that my car is the same year as yours and I've got well over twice as many miles as you.

Oxygen sensors aren't too bad to do, and in the years that I've been working on cars, I have seen no damn rhyme or reason to when they decide to go bad. So even with 38k miles on it, it's possible.

The connector on the throttle position sensor is a problem area for both Neons and SRT-4's alike. I've already had to fix mine. I had a loose connection on the ground pin and the computer would freak out, not knowing where the throttle was. Personally, I got a TPS-specific code when mine went, but it's certainly possible.

BlackRoseRacing · Post by **BlackRoseRacing** » Sun Jan 06, 2008 8:20 am

P0171 $77 1/1 Fuel System Lean

Verification:
Verify the vehicle complaint. Monitor fuel pressure and check for fuel contamination. Review the baro reading and coolant temp readings. There are several different inputs to the PCM that may result in this code. Please review the below recommendation.

Recommendations:

Explanation of possible cause for a FUEL SYSTEM LEAN CODE The Fuel System Lean code is set when: Short Term Compensation multiplied by Long Term Adaptive reaches a predetermined value. The actual number varies make model, but in general this will be highly positive when the condition set. Usually either short term or long term will be at +20 % or higher. The adaptives become higher when the PCM increases the injector pulse width in attempt to make the oxygen sensor switch uniformly about the PCM's oxygen sensor goal voltage. This means that the oxygen sensor is producing a voltage that is close to zero volts ( 0v ) consistently indicating a high oxygen (lean) state in the exhaust. The causes of the oxygen sensor reading a lower voltage usually falls into three main categories: 1 )Too little fuel, 2) Severe engine misfire, 3) The PCM is being provided with the improper information. THE FOLLOWING IS A GENERIC LIST OF POSSIBLE CAUSES. THE LIST IS PROVIDED AS AN EXAMPLE OF POSSIBILITIES. SOME OF THESE MAY NOT APPLY TO YOUR SPECIFIC VEHICLE. IT IS YOUR RESPONSIBILITY TO DECIDE WHICH COULD APPLY. THIS IS NOT A COMPREHENSIVE LIST : MERELY THE MORE COMMON CAUSES. 1) NOT ENOUGH FUEL -- there is an abundance of left over oxygen in the exhaust after combustion. -- This excessive could be caused by any of the following: TOO LOW OF FUEL PRESSURE-(including restricted fuel pump inlet filter, bad pump, defective pump, restricted fuel filter ) INADEQUATE FUEL VOLUME FROM FUEL PUMP ( Should deliver 1/2 liter in 7 second fuel pump actuation time) RESTRICTED INJECTORS-(both inlet screens and deposits at the injector pintle.) WRONG INJECTORS DEFECTIVE PURGE SYSTEM- (purge system is the source of a vacuum leak) 2) SEVERE ENGINE MISFIRE- although OBDII equipped vehicles have misfire detection; earlier vehicles and heavy duty truck do not. If the cylinder misfires the oxygen will simply pass through the cylinder rather than have combustion occur and the amount of oxygen in the exhaust will be high. 3) PCM IS BEING PROVIDED IMPROPER INFORMATION- If the PCM does not receive proper sensor readings it will not deliver the proper injector pulse width for conditions. The following is a list of sensor problems that could cause a fuel system lean code: COOLANT SENSOR CALIBRATION (sensor is reading much warmer than the actual engine temperature). OXYGEN SENSOR CIRCUIT PROBLEM- ( this includes O2, O2 sensor wiring including the signal, sensor ground, and heater circuit wires the O2 sensor must also be installed tight.) MAP SENSOR CALIBRATION--One of the most important readings for testing a MAP sensor is the voltage reading obtained with the DRBIII with the ignition on and the engine off. This voltage reading is important because the PCM uses this for calculating barometric pressure. If the PCM does not "know" the correct air density from the MAP sensor (baro. reading) it will have to drastically change the fuel curve through the adaptives to get the proper response from the oxygen sensor. Below is a chart of key on MAP sensor readings for a given elevation. You should get to know what is normal for your area. Elevation (feet) Baro Reading (in.-hg.) MAP voltage 0 (sea level) 29,92 4.6v 29.67 500 29.42 29.17 1000 28.92 28.67 4.4v 1500 28,42 28.17 2000 27.92 27.67 2500 27.42 4.2v 27.17 3000 26.92 26.67 3500 26.42 26.17 4.0v 4000 25.92 25.67 4500 25.42 25.17 5000 24.92 3.8v VOLTAGE SENSE-- The PCM compensates the injector pulsewidth based upon charging system voltage. The higher the voltage=> the stronger the magnetic field opening the pintle valve in the injector. The PCM compensates for this condition. If the PCM sense a higher voltage than the voltage applied to the injectors the Fuel System Rich Code could also result.

hound9164 · Post by **hound9164** » Mon Jan 21, 2008 1:51 am

Yeah, i finally had to take it in to my mechanic. tomarrow we see whats wrong.

why, o why did i think an american car would last at least 38K miles without a major issue. hell, i blew an emissions-control part at 7K. time to get a toyota lol. or a non-fuel injected engine i can actually fix.

Panhead · Post by **Panhead** » Mon Jan 21, 2008 2:08 am

its not that bad. toyota just had a recall not long ago on there tundra's for camshaft failures, about 500,000 trucks were recalled. its not as bad as you think.

Post by **jonnymopar** » Mon Jan 21, 2008 9:27 am

HA! My girlfriend's family owns 3 Toyotas. All have 4 cylinders which I think is what Toyota does best. Two out of three have less miles than my car (86k). I put more work into each of those cars than I do my Neon. Electrical, air conditioning, emissions, you name it. But of course, Consumer Reports doesn't have anything written about that.

Here's to hoping that it's a simple problem with your car.

Panhead · Post by **Panhead** » Mon Jan 21, 2008 11:38 am

they try to keep it to themselfs so they won't be losing car sales.

Post by **racer12306** » Mon Jan 21, 2008 12:24 pm

I guess the big question is, why didn't you take advantage of the 7 year 70000 mile powertrain warranty? Even if you weren't the original owner it is transferrable.

Also, just because your car had a problem doesn't mean all domestics have problems early. My car has 77000 miles on it, the only little problem I had was an axle seal leak, but thats no big deal. I also just replaced the cam position sensor, again, no big deal.

My sisters neon has 105000 miles on it, no problems.

My moms Ion has 70000 miles on it, no problems.

My fiances Jeep GC has 91000 miles on it, has a slight tap, but that is very common on the 4.0, no problems.

My old shadow had 140000 miles on it, no problems.

My monte carlo is 23 years old and has 90000 miles, it broke a shifter cable 4 years ago. I screwed up the back brakes, and the transmission problem was previous owner envoked. aka no major problems.

My dads old 91 diesel ram had 220000 (i think) miles on it. replaced a TPS (or whatever the diesel equivalent is) at about 170000. no major problem.

my dads current 05 diesel ram, 60000+ miles, no problems.

should I stop here, or keep going?

quicksilvr · Post by **quicksilvr** » Sun Feb 10, 2008 11:53 pm

To revisit this: MY car just threw this code yesterday. I noticed it had started idling like it a had a big cam in it....and I figured I better check the codes. Sure enough I've got this code now too. I figure it's because the new exhaust system, and the freakin cold weather here. After reseting the computer, it came back within 10 minutes of driving. Arg. I guess I'll live with it and hope it goes away when it warms up a little. If not, MS isn't too far down the road. Ah tax refunds......

hound9164 · Post by **hound9164** » Sat Feb 16, 2008 4:04 am

UPDATE!

i had to get a new o2 sensor from the dealership. i had a bosch replacement from advance auto, but it made matters worse. only the exact dodge part worked. code disappeared immediatly and its ran smooth since.

worst of all, my mechanic refused to touch the neon. he said he was in no mood to chase electrical ghosts on another dodge. umm, isnt that what he gets paid for? to fix cars?

BlackRoseRacing · Post by **BlackRoseRacing** » Sat Feb 16, 2008 10:08 am

^^^
Your not the only one I told to get rid of the Bosch replacement O2, for some reason Mopar PCM's like Mopar O2's and not the aftermarket....

NickKo · Post by **NickKo** » Sat Feb 16, 2008 11:21 am

hound9164 wrote:UPDATE!

i had to get a new o2 sensor from the dealership. i had a bosch replacement from advance auto, but it made matters worse. only the exact dodge part worked. code disappeared immediatly and its ran smooth since.

BlackRoseRacing wrote:^^^
Your not the only one I told to get rid of the Bosch replacement O2, for some reason Mopar PCM's like Mopar O2's and not the aftermarket....

I have (sucessfully) used aftermarket / Bosch O2 sensors from Autostoned on one of mine.... but this was on one of my 1ST gen Neons.

2nd gens may be different .... I will have to keep this in mind.

Keep in mind that Bosch / Autostoned offers two different kinds of O2 sensors for your car .... "bolt-in" direct O.E.M.-type replacements, and a "custom-fit" or 'universal' type where you have to cut and splice/solder your own wires to fit.

I made the mistake (once) of being a cheapass to save a few bucks and tried to use the 'universal' fit job (*cough, gag, choke*).
I must be a Neonite, I can't believe I was so cheap.

I GAVE UP on the idea of trying the 'universal fit' (cough) O2 sensor after losing the guts to cut up wiring and try to solder the connector in and pray that it would work.
I went back to Autostoned, and exchanged it for the "OEM type" replacement. It was only, like, $5 more. Why did I bother to try saving the $5 ?

Thanks for the tips, guys.

-Nick

Post by **jonnymopar** » Sat Feb 16, 2008 1:56 pm

The Mopar units that I've used were NTK units. Just real good stuff. I've sworn off Bosch sensors in any FWD Dodge car.