2001 Expedition; dying and will - NEW alternator and battery

[foreeverford]

ir need help 4.6 engine 1998 f250 puts codes 171 174 and occasionly 455 replaced all exhaust system .thank you

[Karl]

Code P0171 and P0174 are for lean on bank 1 and 2.
P0455 is an large EVAP system leak.
Did these codes come up after you replaced the exhaust, or did you replace the exhaust to try to fix these codes?

What exactly did you replace?

[tmcgovern80]

i have a ford f 150 1997 with four wheel drive . 2 years ago i had a problem passing the emissions test and ended up getting a egr valve replaced and it passed last year i did not drive 5000 miles so i did not need an emmisions test . so this year i have driven my truck over 15000 miles and will need the test . i have a friend that hooked up the computer to the truck and said there is no light and no codes. he told me i need to drive some more to complete the cycle.. well for 2 years i never had a ck engine light on? and i have driven for at least 500 miles ? dont want to pay the emissions test if i know it will fail ? what should i do?

[carriedi]

states vary in what they require to pass emissions testing. But the ones that look at the OBDII will look for any codes and will look for the readiness monitors. If you have monitors that have not run some states will not let the vehicle pass. You will need a temp. license so you can drive the vehicle until the monitors have been run and passed. The monitors have certain conditions that they look for. Some require that the gas tank be between 1/4 and 3/4 full. Some require certain temperatures to run. You are at the mercy of the manufacturer as to how long it will take for all the monitors to finish.running their testing.

however that being said, if you passed your emission test a while back and you haven't changed anything or your battery has not gone dead you should still have all the monitors run from you last test a couple of years before. If you clear codes or if you battery goes dead then the monitors could have been reset and you will just have to drive the truck until they all run.

[davlor2]

3.8L engine. Initially getting codes P0301, P0302, P0303 and P0172. Idle is smooth but the van will not go over 40MPH. The engine shakes under load and the check engine light flashes. Plugs and wires are good and I just replaced the coil pack. The van does have a small exhaust leak, but that is not a new thing. MAF is ok. I cleared the codes and drove the van until the engine light came on, now it shows P0300. Any thoughts would greatly be appreciated.

[carriedi]

use a scanner and do a cylinder contribution or a misfire counter while you are experiencing the running bad condition. see what cylinders are missing and see what your fuel trims read. Verify that your fuel pressure is 28 - 45 running or 35 - 45 key on engine off with key cycled on.

you could have a fuel problem, a plugged cat, injector problems, dirty MAF, Bad O2 sensor, it all things you will have to check out. you can look at most of the computer inputs and readings with a scanner on the truck

[glminor]

Installed a new alternator, battery is GOOD. Dying when driving. After installing new alternator, and charging battery twice for 2+ hours each time; start engine, but when remove the negative (or positive) battery cable engine dies. 4.6

NOT sure what's causing the issue and HATE to take it to the Dealership.
Thanks in advance for any troubleshooting tips or remedies with the same problem.

JUST started and died twice while driving. (2) jump starts started the engine, but soon died - after about 3 minutes of idling.

NO engine codes
Thanks again,

Gary

[carriedi]

first thing is never take the battery cables off with the engine running. the regulator looks for battery voltage to know how much to charge the battery. It can spike up and damage electrical components like computers.

Why did you change the alternator? and how do you know you have a good battery? Do you have a volt meter?

a good battery should have a voltage reading of around 12.6 volts. engine running, the alternator should charge around 14 volts, depending on battery needs (13.8 to 14.2 after the engine has run for a while after starting the engine)

Need more information. Do you believe that the alternator or battery have something to do with the engine dying? What makes you thing they are related? When the engine dies, are you able to restart it right away? Why did you jump the vehicle?