I noticed today the when I started my truck that the exhaust really smelled like all the fuel wasn't burning, What could it be? I have never changed the plugs in it and it's reaching 84,000 miles? Any Ideas? Thanks guys!

 

what year is it? motor? if its an 05 5.4 then it may be the injectors. i'd have them checked at the dealer. they extended the warranty on them so they'll be replaced for free if they are .

 

It's an 04 with the 4.6

 

in that case you may just need a tuneup. is it running rough or weak or getting worst fuel mileage?

 

It seems to run and idle great, It is getting worse mileage but I thought it was just from the bigger tires, but my truck wasn't driven on a daily basis for about a year because I was deployed overseas, so yeah could just need a tune up. Could it be the o2 Censor?

 

its a possibility. is there a check engine light? the front o2's are the ones that cause it to run rich or lean.

 

No check engine light? no stored codes? You could replace the front o2s they might be a little weak but it would throw a code if it was to far out of whack. Probably just the cold.

 

Nope no light

 

jethat may be right about the cold. how long has it been running when you smelt it running rich? it may be running rich because it isnt up to temp yet.

 

Your probably right, I smelled it when I first started it up, and it's really cold out. Thanks for all your expertise guys!! Im sure you just saved me alot of money!! Thanks again.

 

I have a 97 5.4, all stock and its running rich. Throws a code. Started a few weeks ago. I have read and cleared it 3 times with in that time. Now I am tired of it. I was thinking O2 sensor. Ford installed enough of them. But why wouldn't it through an O2 code? Hate to replace them. They're expensive buggers.

 

First this is a 2 year old thread.

If you had the code read, then what was it? Can't help if we don't know what to look for.

 

Post the exact DTC. If you can't remember, have it scanned again and write it down.

Also, if you can't find an answer searching, -that's when you start a new thread.

 

I did find an answer just not a detailed one. Didn't know there was a expiration date to threads either. Matts ford suspected an O2 sensor and I suspect the same. I just wanted some more information on the matter. I'll start a new thread.

 

No expiration date, it's just you might get better response with a new thread with your specific issue. We've seen some as old as 9 years old. Things change as we get smarter!

Also the "P" codes are very very very helpful for someone to help you out. So did you have the codes read? It also helps others fix their issues if you post them and what you did to fix it.