My p0171 code on my 2000 kia sephia 1.8L 5speed.
Ok since this is the first thread that pops up on google, I wanted to post my experience to this thread to help people with the same problem in the future.
I have a 2000 KIA Sephia 1.8L 5speed with 138,xxx miles on it. I bought it and drove it about 120 miles and the check engine light came on. It had a p0171 code. I did not reset the computer, and I kept driving. I noticed that when I would take it easy on the car (& My a/c was on.) that the CEL would go off. But when I am harder on the car (& a/c off.) the light would come on.
So I went to google and started looking at what things could be wrong with the car.
- Intake air leaks (Vacuum leak.).
- Bad o2 sensor.
- Ignition misfire.
- Faulty fuel injectors or fuel pressure regulator.
- Incorrect fuel pressure. (Supposed to be more that 30psi & less than 60psi. - Around 45psi under load.)
- Lack of fuel.
- Faulty Mass Air Flow sensor (MAF).
- Incorrect Positive Crankcase Ventilation (PCV) hose connection.
So.... What did i do first?
I thought, oohh.. I do have an exhaust leak, let me fix that. So I did. Next thing I know 80 miles down the road.... My CEL comes back on and it is the same code.
Next I check the fuel pressure - it was fine.
While I am under the hood, I think to myself... Let me check for vacuum leaks.
I check and find that the ribbed part of the air intake hose has a crack on each rib...
Yep - I bet that is the problem.
So I do some looking around and find that hose on eBay for $35-$40. Local parts stores (Autozone) wants $65. I didn't want to go to the junkyard and get one because I fear I would have the same problem again down the road, and I wanted a more permanent fix.
So what I did for now, (Until I find something better.) is a 3 inch flexible air duct.
I got mine from Autozone for $20. Mine is a "Spectra 8741".
It comes with two rubber fitting and the air duct itself.
That part number if for the black one. They also offer red, blue, and silver.
Since the air duct tube is 3inch's in diameter, I cut the pieces of the stock air intake hose where the hose clamps go on each side and pushed them into the rubber pieces that the air duct came with. The two pieces of rubber are not mounted to the duct so you would have to push the rubber pieces onto the duct without pushing the original hose pieces out of the rubber. Then I reinstalled the hose clamps using bigger screws and I also installed hose clamps on both sides of the air duct where the rubber meets the ducts. I was not comfortable with the seal it had, I though it was going to leak again.
I also wrapped the little rubber hose that connects the air box that sits on the radiator and goes into the filter box with electrical tape. After I washed it.
I did all that and replaced the filter at the same time.
Side note - All of my screws that were holding the top and bottom of my air filter box were broken. So I used screws with washers and nuts and I was able to fix that problem.
Here are some pictures.
Here is the code on my scanner.
Here is my stock air intake hose.
Here is one of the holes on the ribbed portion.
Here is the new setup.
Spectra 8741 3" flexible air duct.