The Check Engine light is on in my 1998 4.6L F150 and my OBD2 diag tester tells me the code is for an "Evap Gros Leak". Any idea what this is? Pardon me, but I haven't really researched this yet. I was thinking maybe someone would know off the top of their head. The truck runs fine, there aren't any puddles under it, and no leaking gas smells! Dennis

 

Hey,
I have the same problem on my '97 f-150 w/ 185k+ miles. I did some googling and found this website. I haven't tried the fix but I will look in to it on 12-14-03. I'll let you know what I find.




http://www.visi.com/~rhanson/obdII_codes-full-text.htm

 

check your gas cap fort being loose

 

did you ever put gas in it while it was running?
that could be the problem

 

I just fixed that same problem on my 98. Check between the battery and firewall. There is a vacumm line connector with 3 small and 1 large vacumm line. Mine had chaffed against the battery and wore a hole in 2 lines. After repairing the lines and resetting the computer all is well now.If it's not that ,then you have a vacumm leak in the EVAP system, The decal on the fan shroud helped me. Also it could be a purge relay or solenoid or as simple as a bad gas cap. GOOD LUCK !!!!!!

 

hey guys,

everyone nailed the topic right, in my ford shop evap leaks can be
either miserable to find or something as simple as bad gas cap or leaving the engine running when filling up can cause a gross evap leak. ford started using the new evap system a few years back to keep emissions to a minimum by keeping all fuel vapors in the system and burning it off.

 

Thanks for all the good suggestions. Haven't found problem yet. I did a search on the NHTSA site and found several Tech Service Bulletins addressing this problem on my 1998 F150. Only thing is, they only show the summary, not the whole bulletin. Anyone know how to get a look at a Ford service bulletin?