Ford Ranger Forum - Forums for Ford Ranger enthusiasts!

Go Back   Ford Ranger Forum - Forums for Ford Ranger enthusiasts! > > >
Forgot Password? Join Us!

Welcome to Ford Ranger Forum

Thread Tools Search this Thread

Old 02-18-2011, 11:10 AM
Moedad Moedad is offline
Learning to use the forums
Join Date: Jan 2011
Posts: 4
Default CEL Puzzle

The CEL has been on for a long time on my 99 Ranger. Various shops and people have tried to diagnose it. Two years ago I cleared the light and the truck passed the CA smog test with no problem. CEL came back on shortly after the test. In the last two years I've tried off and on to figure it out with no success. The code is invariably the P0171 code, lean on Bank 1. I've done vacuum leak checks, visually examined vacuum hoses, cleaned the MAF sensor, replaced fuel injectors, O2 sensors, fuel pressure sensor, gas cap (almost all of these things for sure needed replacing).

This week it was time to get it smogged again. I cleared the light and took it in and it passed with flying colors. They check vacuum, fuel pressure, EGR, and a bunch of other stuff. Later in the day, the CEL came back on again. The truck runs great. I'm stumped. The only thing I haven't done is check/replace the DPFE sensor, but why wouldn't that show up in the smog test if it was bad? Maybe the MAF sensor is bad (but clean )? Or the connection to the MAF is corroded? Starting to think it's an electrical thing.
Reply With Quote
Old 02-19-2011, 06:55 PM
cowboykilroy cowboykilroy is offline
Like the Forums
Join Date: Dec 2010
Posts: 41
Default Re: CEL Puzzle

Not sure what 4.0 you have if sohc I cant help. If ohc I have a 97 that had a similar problem, .I finally took it to a dealer for the pinpoint diagnosis turned out to be upper intake gaskets and fuel rail gaskets and that was the answer .They wanted over $600.00 to fix. I fixed it myself for $15.00 dollars in gaskets and an afternoons work . So for $89.00 test at Ford it was worth it. They were exactly right on the problem.
Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Similar Threads
Thread Thread Starter Forum Replies Last Post
multiple CEL codes need help wangbungal 3.0 Vulcan Tech 2 02-10-2011 09:49 PM
10 codes but no CEL? CornFedBeast 4.0 SOHC / 4.0 OHV Tech 8 01-15-2011 03:14 PM
Cel mehdi1993 3.0 Vulcan Tech 2 11-12-2010 09:46 AM
CEL keeps coming on 1freaky1 4.0 SOHC / 4.0 OHV Tech 26 03-08-2010 10:29 AM
2004 Ranger starting puzzle - please help gregatvb General Tech 0 01-24-2010 01:01 PM