I ran my car for 10k miles on 93 octane before I got a tune. Higher octane gas will not damage the motor. They probably told him to change gas to try to eliminate the possibility that whatever gas station he fills up at has bad gas.

 

Im under the impression higher octane gas will have adverse effects on a motor. If I'm correct, which I never am, isn't higher octane gas less explosive/combustible? Therefore you would need an engine with more advanced timing or higher compressionto correctly combust the higher octane fuel. This can be done with a tune that advances the timing. So using higher octane in a less advanced timed engine, like the stock engine,would result in a good amount of fuel not combusting, causing less power and most importantly, more carbon buildup.

 

Ding ding ding!! We have a winner. Running 93 in an engine tuned for 87 does not fully combust the fuel. It won't HARM the engine right away, its just a gradual build-up over time. Maybe at 50K to 70K miles it might start to have an adverse effect. As far as additives are concerned, those are added at each gas station. Lots of times the fuel is delievered in a generic tanker truck, often by a company that has extra fuel left over, and does not want to return emty. When the fuel is delivered to the station, the additives for that specific brand of fuel are added.

 

Take out the K & N its useless.Put back to stock and start there.....Try diconnecting the battery for a while to the computer will restart...

Weird, i know...

 

i am the first owner, ony thing i have done is put a k&n on, dealer said it might be a the problem but it happend before as well...

Ill ask the dealer to take a look at what u are suggesting.

It is a completely random thing about every 2-3 weeks. most times when trying to "floor it" to pull out on a highway.. sometimes with granny driving.
And 30 seconds after it starts, its running perfect. No codes nothing out of the ordinary. It even revs as tho you are driving normally but the car sounds like crap and barely moves.

I have switched between 2 BP stations that are close to home and work. and back to 87

-Its only got 6700 miles on it!

The Latest: I took it in to see a "mustang specialist" he checked for any new codes and nothing... So he checked with ford to see if there were any factory bullitins on this model year. nothing as of yet.....
so since they cant pinpoint and since its relatively a new model year he said to just keep checking back to see if there are any updates.

 

so -check for CAI fit.
-narrow down the gas stations
- see if they cant give me a data recorder for a few weeks.

 

I completley forgot.

This happened to me, not so much on the back fire side but the power thing.

I am confident it is the fuel pump, air in the system. Ford replaced mine for that exact reason.

I believe it fell under TSB "hesitation after long cruise/loss of power"

 

The only thing you are hurting with 93 Octane gas is your
wallet. This no throwing codes is a stumpifier. Just about
anything out of the ordinary will throw a code.
Are the #s 666 anywhere on your licence plate
or maybe etched onto one of the heads.
Better check just to make sure.....

 

I just posted a similar experience:

Bogging when Hot

 

the "mustang expert" mentioned that but said my situation didnt match, so no fix for me.. i think im going to insist on it tho...