2001 2.3L P0171 code - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

tomcas · 07-18-2007, 09:12

I'm getting code P0171 on my 2001 Mazda B2300 2wd manual with 53K miles. It runs fine and gas mileage is good but I have a state emissions test coming up soon. I cleaned the MAF but after clearing the code it still comes backs after a few days. It seems there are a crap load of possible causes including vacuum leaks and fuel delivery problems. I'm looking for tips on narrowing the possibilities or experiences other people have had with this problem.

dryelf327 · 07-18-2007, 13:02

You don't have any kind of performance intake do you? I know of some K&N cold air intake systems making engines run lean. My other concern would be the EGR system. You can clean out the valve but with only 52k miles, it seems premature for gunk to be clogging the valve.

tomcas · 07-18-2007, 13:17

It's completely stock. No mods at all.

tomcas · 07-19-2007, 10:34

I found the problem. The vacuum hose connecting the intake manifold to the fuel pressure regulator was severely cracked at both ends. It almost looks like it burst at one end. Ford needs to use a higher temp rubber like viton or silicone. The color of the truck is black but if 5 years and 50,000 miles can do that much damage in New England what happens down in Florida or Arizona?

dryelf327 · 07-19-2007, 11:14

Glad to hear you found the problem.