so i have a crappy hypertech PPIII on my 97 f150 with 4.6 and 4r70w k&n intake and cat back with hollowed rear cats, otherwise stock. now my problem seems to start under heavy load in the higher rpms. it can be a racing start to get on the freeway on ramp or just cruising up a hill. if i let up it will stop but like when im going up a hill as it gets more of a load (gets steeper) the more i have to let off. its really irritating because its not like this tuner is worth its weight in gold but it really helps with the down the highway behavior. i think mostly trans behavior. there isnt any mpg difference and no noticeable power difference. i know i need a better tuner but is this common for this one? i am using 91 from am/pm. thanks

 

if you set the truck back to stock, does it still have the same problem?

 

well it never did it before the tuner on 87. so im waiting till monday for the drive to work to test that. the crappy thing is i never noticed till one day when i had my radio off. typically i have my radio up pretty loud cuz my exhaust is pretty loud....has any one else ever had this problem???

 

If you have done all the maintenance properly on the truck - MAF, TB cleaning, no vac leaks, new fuel filter, good plugs, fresh front O2's, functioning EGR/DPFE, etc, etc, and it's still doing this, run stock & GET RID OF THE POS BEFORE YOU GRENADE YOUR ENGINE.

 

If it doesnt do it on the stock tune then you know its something to do with your tune. Do you have the ability to make adjustments to it. Try taking out a degree of timing or adding a little bit of fuel . That should take care of it.

 

That tuner is for a completely stock truck.

 

A PP III is a discontinued legacy device. You cannot adjust for timing or fuel. Only shift points/firmness, and gearing.

OP - are you using the correct tune for the octane you are running? If you have the 'dual fuel' option, try that - it lowers the octane requirement to 87.

Again - the presumption is that the truck is copacetic w.r.t maintenance.

EDIT - Yep, Norm's right. Try ditching that intake - does nothing worthy anyway ....