[radracing]

I bought my 99 f250 about 2 years ago. When I bought it, it was shifting messed up. It will take off in 1st gear, and not shift to 2nd gear, about 70 percent of the time, unless I lift my foot off the throttle,it will go into 2nd, then it would go into 3rd, then skip 4th and go into overdrive. If I accelerate, more then half throttle, before it goes into overdrive, it will go into 4th for abouut 2 seconds, then shift to overdrive quickly. I ran a scanner and it gave me a code for the shift solenoid. I put a brand new solenoid in the tranny, and it still did the same thing. I ended up getting the transmission rebuit with a new torque converter, new filterand new fluid about 15 months ago and it still had the same problem. Ive been driving it like this for awhile know. Now here is the weird part. I was driving the truck most of the day today, and about the last hour of my driving, I decided to turn off the overdrive. It still shifted the same way for 10 minutes, and then I took off from a dead stop, and it went through the gears perfect. Better then ever. It ended up shifting perfect every time until I got home. 10 minutes into it shifting perfect, I noticed the overdrive light flashing. When I got home I hooked up the scanner, and it gave me codes, p0781 and p0732. It told me what the codes are, but what is making it have this problem. Please help ASAP. 2 years of this is enough. Thanks for the help.
Sorry for the long post.

 

[radracing]

Someone please help. I was thinking it might be the valve body. Tell me what you guys think.

 

[radracing]

The day after it started shifting right, I cleared the codes, and put my custom tune back on, and it went back to shifting messed up, and no more codes.

 

[CT Performance Inc.]

Who's tunes?

 

[engineer101]

have you tried driving it with out the "custom tune" on that may be the problem some of these plug and play tuners are NOT plug and play at all

 

[radracing]

I don't know who's tune it is. It was on there when I bought it.

 

[radracing]

I have drove it with out the custom tune. It does the same thing. It only worked good that one time, when I turned the overdrive off, with the custom tune off.

 

[engineer101]

ok so before you hooked the custom tuner up to your truck {before you bought the tuner} it had this issue? and where did you buy this tuner from? what kind is it specific make and modle if you know it if not then just the make

 

[engineer101]

also when you replace/ rebuilt your trans did you bya nny chance check the oss sensor located at the to rear of the transmission to see if it was damaged in any way maybe from the prior owner or wear and tear over time. there are may things that can cause codes to be set. low voltage at the alt. may set a code but first things first set your tuner back to the stock setting on it, then unplug it drive it around let the ocu realize that there is no turner, in this process check the oss agian on the top rear of the trans, if it continues you may end up having to replace the trans sorry but youve replaced it once on a rebuild might be time for a new one.

 

[radracing]

When I bought the truck, it allready had the tuner. IT wasnt shifting that bad when I got the truck, but it gradually got worse. It has a SCT SF3 tuner. I didnt check the os sensor.

 

[engineer101]

Ok at this point check your oss and from there the only thing I can say to do is drive it in every position on the turner for atleast 25 miles to get a good run and to get up to speed and cruise see which. Setting is smoother

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