Check your vacuum lines


ByeEnzo

GT
Mark IV Lifetime
Le Mans 2010 Supporter
Dec 10, 2005
2,299
Fort Worth, TX
I was going to take my 2005 FGT in for routine state inspection this Monday. It threw a CEL when I fired it up. Drove fine so I thought it was an O2 sensor or gas cap. Read the code later on and it was for a lean condition at the O2 sensor. It also started to idle rough in the warmer afternoon air. Rich Brooks gave me some advice…he’s def the best. Turns out one of my vacuum lines off the intake had a big split in it. I guess 63k miles of engine heat got it. Quick run to auto parts store for a rubber line…back in business…cleared the code…and passed the Texas OBD inspection.


IMG_0131.jpeg
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
4,281
Great that you got some good advice and the ECU was trying to help you as well. Lean condition as reported by O2 sensor(s) is most often un-metered air coming into the engine. The ECU can't make any sense of it... the Mass Air Flow (MAF) tells it how much air is being ingested and then pulse duration for the fuel injectors can be set accordingly and then a quick confirmation with the O2 that A/F's were on the money... but whoa... too lean! The ECU adds more pulse duration... O2 still confirms lean. ECU realizes that it can no longer control the engine and illuminates the check engine light.
 

HighHP

GT Owner
Jun 3, 2019
469
Spokane, WA
Thanks, all good info.
 

PeteK

GT Owner
Mark II Lifetime
Apr 18, 2014
2,469
Kalama, Free part of WA State
Yes, thanks for the heads-up. Since I'm past 85Kmi, I better go check mine too.

Along with the rear hub nuts.
 

twobjshelbys

GT Owner
Jul 26, 2010
6,189
Las Vegas, NV
Did you have to run the whole drive cycle to get all of the obdii tests clear?
 

ByeEnzo

GT
Mark IV Lifetime
Le Mans 2010 Supporter
Dec 10, 2005
2,299
Fort Worth, TX
Did you have to run the whole drive cycle to get all of the obdii tests clear?
No…I cleared the codes with my scanner tool and then drove the car to work…about 15 miles. At end of day, got it inspected after about a 3 mile drive. Go figure.
 

Stef

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Apr 5, 2009
1,111
Southern California
Good to know this. Thanks for the info.
 

fjpikul

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Jan 4, 2006
11,680
Belleville, IL
How can you work on an expensive car with those cheap Harbor Freight tools or something bloody from the OR. Shame on you.
 

Mule Air

GT Owner
Jan 28, 2019
46
NC
No…I cleared the codes with my scanner tool and then drove the car to work…about 15 miles. At end of day, got it inspected after about a 3 mile drive. Go figure.
That's crazy. I am over 500 miles and mine isn't ready. I probably need to take it easy...:sleep:
 

twobjshelbys

GT Owner
Jul 26, 2010
6,189
Las Vegas, NV
That's crazy. I am over 500 miles and mine isn't ready. I probably need to take it easy...:sleep:
Follow the drive cycle doc step by step. Then specifically target the steps for the ones it missed.
 

Mule Air

GT Owner
Jan 28, 2019
46
NC
Follow the drive cycle doc step by step. Then specifically target the steps for the ones it missed.
I tried a couple of them that I found online. Do you know if the one you posted below works?

 

twobjshelbys

GT Owner
Jul 26, 2010
6,189
Las Vegas, NV
I tried a couple of them that I found online. Do you know if the one you posted below works?

The one from obdii.com seems to take forever, as does the basic site. Don't know what's going on and if it's permanent or temproary.

Nonetheless the manualslib version is the same.

Google search for "Ford emissions drive cycle" shows many more.
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
4,281
Also in the GT Service Manuals....
 

twobjshelbys

GT Owner
Jul 26, 2010
6,189
Las Vegas, NV
Also in the GT Service Manuals....

Which I extracted and posted here:


I got tired of stale links or the introductory detail-less generic cycles that were referenced elsewhere and extracted the service manual version.