Question on clearing trouble codes

2000 Ford exploder xls
engine size v6
131000 miles

Failing the ODB test for emisions with the infamous P0171 AND P0174 codes. I must repair this problem to pass an emissions inspection.

I did a search in this forum of the P0171 code. Lots of good stuff there. I have many things to do and little time. The inspection sticker expired Nov 30, and I (she) has already gotten a warning from the police.

History:
Last year I had the same problem same codes. I sprayed (literally washed) the engine with carb cleaner and found no vacum leaks. Then I sprayed some carb cleaner in the DPFE/EGRsensor and the problem cleared. Now its inspection time again and I learned that the CEL is on again. I have no idea how long becasue girls drive this vehicle and they have never noticed the bright orange "CHECK ENGINE" light next to the speedometer. GEEZ! Anyway, I got the same P0171, P0174 codes again. I just replaced the DPFE/EGR sensor this time (Ford said this was the culpret) and I cleared the codes. I reset the trip and waited about 100 miles and same codes are back again. Whenever I clear the codes the following (5) sensors go to a NOT READY state:

1-Catalyst
2-Evap
3-O2 Sens
4-O2 Sens Htr
5-EGR Sys

So im going to be testing and fixing things one at a time. Then I have to wait for the sensors to return to service and tell me whether the fix was successful or not.

My actual question: Once codes are cleared. How long does it take the "NOT READY" sensors to return to service? The inspection station tells me 60 to 100 miles. AND, in laymans terms what is considered one drive cycle? I read the 'drive cycle' term on one of the threads.:1zhelp:

Just need some clarification.

Thanks.

You may want to visit a thread on the Taurus forum regarding the P0171 and P0174 codes, http://www.automotiveforums.com/vbulletin/showthread.php?t=768631 (file:///C:/Documents%20and%20Settings/raschmid/Desktop/KV/CLS/CRGs/CLS%2050/KCL%202%20Transceiver%20Assy%20SN050_Whitepaper_FO UO_Draft%20rev%20C.doc)

As for what it takes to complete the drive cycle, there is an entire paper that Ford put out regarding what it takes to complete a drive cycle for the emissions monitors. I'll see if I can find the document on my home PC tonight. In the mean time, you may want to visit http://www.obdii.com/drivecycleford.html for their description.

-Rod

Thanks Rod,

The first link maps to a file location on someones hard drive.

Thanks Rod,

The first link maps to a file location on someones hard drive.

Ooops, you're right. I'm glad you couldn't see that file. :disappoin

I've corrected the link in the above post, it should work now.

-Rod

Another quick message about teating the vacum system. When checking for leaks at idle speed the pressure should be well below the 'under a load' pressure. What rpm will simulate the vacum system under a load? Do you have a diagram of the entire vacum system (all hoses and lines) on the V6 engine?

For the vacuum test, you could try running the engine at 2000 rpms. This evidently provides sufficient load since that's the engine speed recommended in the EEC-IV system prior to performing the KOER tests to get the engine up to operating temperature in 2 minutes time.

If that doesn't seem sufficient, then I suppose you could very cautiously try power braking the vehicle. You'd want to be sure the wheels are properly chocked, parking brake set, firm foot fully on the brake pedal, etc. That would certainly load the engine for short duration checks.

The factory service manual for the 2000 probably has vacuum diagrams, but I'm not sure it will show much more detail than the emissions diagram under the hood.

If your Explorer has the manual HVAC controls, there are probably a fair number of vacuum lines under the dash as well.

I'll try to check for a diagram this evening. Which V6 engine do you have, the SOHC or OHV?

-Rod

I have the SOHC but im thinking that im getting to that "im done with it" stage. I changed the egr sensor, pvc valve and put a couple of clamps on the hose. Cleaned the MAF sensor. Local mechanics tell me its probabaly the O2 sensors. But I cant see them both being bad at the same time. AND! Becasue they are telling us the fuel is too lean is indication that they seem to be operating correctly, isnt it? Anyway, I cleared the codes again, drove it about 75 miles and the same codes are back BUT the CEL is not on although the code reader says it is -- which means the CEL bulb is blown. Im shooting at a moving target here and I have reached my $100 do-it-yourself- limit and I am out of patience. I am going to have to bite the bullet and let Ford do exploratory surgery on this thing. What pisses me off is that they (Ford) acts as if this is a new problem with this engine.

Also, if there was a vacum leak under the dash that is sucking enough air to cause a too lean fuel mixture shouldnt I hear air suction when I do hard accellerations? Id still like to see that diagram if you can get it for me.

Ok, AFTER MY BLOOD COOLED I took it to ford and they told me the gaskets was definately sucking air. gasket kit $45. Time to fix it? 6 hours. I take my time. Ford wanted to charge me $580 and keep the truck for one to two days. CROOKS!!!! The original factory assembly was very sloppy. Of the 6 hours I spent one hour cleaning parts and 1 hour putting it back together. Taking it apart was challenging(the EGR TUBE IS A PAIN). Everything is easily accessable. Being 6'4" tall helps too but its still a backbreaker.

A few (out of order)tips:

1 - HANDY MATERIALS: have a few cans of carb and choke cleaner. The intake and the injector plate will need a generous spraying down. Steel wool cleans the surfaces of the injector plate and the mating surface on the car nicely. dont use sand paper or scrapers. An old toothbrush or two comes in handy too have your wd40 around. You can do this mostly with an 7mm, 8mm, 9mm, 10mm, and 1 1/2 inch DEEP sockets. 1/4 and 1/2 inch drive ratchets. Screwdrivers and stuff.

2 - A shop vac or some other sucking device comes in handy to suck all the junk from the valley that house the injectors. When you remove the main manifold housing clear out the junk (toothbrush) around the injectors before removing the injector plate or the junk around them may fall in the holes. A lot of junk sitting in those valleys. If you use compressed air cover the 6 intake ports (duh!) before spraying the junk from the valleys.

3 - 6 STUDS: as soon as you remove the intake, there will be 6 studs that hold down the injector plate. spray(SOAK) them with wd40 right away, let the wd40 pool and absorb several times and allow it time to penetrate so the studs break loose easily. IF THEY DONT BREAK LET THEM SIT FOR AWHILE. (Ford says up to 24 hours) Those studs are about half the length under of what you see sticking up. Be gentle with them. (DO NOT USE AIR TOOLS). If you break one of those studs ...youre screwed!!! The bottom half will have to be drilled out. AND according to Ford, the studs arent easy to come by.

4 - EGR TUBE: Getting the EGR tube to disconnect from the manifold is a pain but it comes off. be patient, rock it back and forth and dont break the plastic manifild. if you do, well ya know ...youre screwed! To put it back on put a little brake grease on it and make sure you dont unseat that seal while pushing it back on. Have a small mirror handy so you can see under it. hate to have to take all that stuff apart again.

5 - INJECTORS: if you get muck in the bottom of the injectors DO NOT spray them with choke cleaner. gently remove it with a q-tip saoked with choke cleaner. Dont damage the screen. (Per Johnny at Ford Service). Also, notice the two seals on them? MAKE SURE THEY STAY THERE. Its not necessary to unplug the electrical plug on them becasue that plastic clip is very brittle. Be patient when reinstalling the injector plate. Dont force it back on, get it lined up on the injectors and seat it using the studs. use your best judgement to keep the plate lowering evenly.