Hey guys,

just noticed something weird this morning. On my way to work whenever i would get off the throttle to hit the brakes my A/F gauge would peg itself at 18, if i hit the throttle again or just coasted and waited after a few seconds the gauge would go back to normal ready of 14.7 or so. I know its not the gauge because when it goes all the way to 18 it feels as if the truck hit a wall, the idle drops like normal, the truck doesnt want to shut off or anything, but i can feel the change.

I have been hunting an SES light that first came on about 2 weeks ago when i installed my K&N FIPK. I was getting the "lean bank 1 and 2" codes. I double checked all my hoses and couplers and i cant find any vacuum leaks.

I cleared the SES light with the Predator and it went away. However, after a few days i got the SES light again, but this time when i check it with the predator it tells me there is no SES code stored. I havent disconnected the battery yet. I had the factory tune in my truck until this weekend. I upgraded the predator and added the 93 non pulley tune to it on Fri. Truck ran fine all weekend.

My fuel pressure holds at about 30 at idle or while crusing at a steady speed on the highway. If i get on it it climbs past 50 like its supposed to. When i get off the throttle it drops to about 26 and then climbs back up to 30.

I will be changing my fuel filter to eliminate that as a culprit.

Any ideas?

 

it is completely normal to lean like that on deceleration and your foot off the accelerator... Nothing is wrong...

 

BINGO

 

Phew, Good to hear that. Now that i added the 93 tune im looking at and listening to everything i can. Just never really noticed that before.

Thanks for the replies guys.

 

Don't worry, it scared the hell out of me when I noticed it too... I did some research and was relieved.

 

Likewise. I was scared *****less when I first saw it too.

 

It's called DFCO deceleration fuel cut-off. My Corvette has a trip computer that shows instant MPG. I have seen 99 mpg on deceleration.

 

I hit 99mpg in my grand cherokee also... only on deceleration though.