I wonder if the hypertech he has is for a non flex fuel truck. It could explain the issues since the flex's have bigger injectors.


EDIT: Part # for flex version is 83008

 

The whole point of the 180 degree thermostat is to make the truck run colder so it will run richer. Thats why all these programmers recommend them because the programmers advance the timing and if the engine gets too hot it will ping or cause early detonation.

 

Well to answer all your questions I do have a 180 degree thermostat but I also have factory electric fans so it really didn't make any difference but I do think it is running at 200 degrees instead of 210 degrees. I have no way of adjusting the fans and as far as buying the truck last year, I didn't know it was flex fuel until I bought some parts for it at the dealership. I think I will check the temperature on the tuner to see where it is running. So if it is 10 degree cooler it will still run richer and also I verified the air fuel ratio with a snap on scanner it is the same as the Hypertech.

 

you cant check AFR without hooking it up to the exhaust
get that through your head please.the hyperjunk and snapon didnt read anything if it was just hooked up to your computer.its reading what the computer is set to not what it really is.


1-if your on the stock tune now with different size tires that effects the mile's on your truck= not being right. wider tire/bigger wheel= lower mpg
2-if your gonna use a handheld use diablo sport
3-all these guy's that have posted are being very helpful,reread all the post's.

 

You really need to go to a tuner and have your truck re tuned.
If you want to know what your AFR Really is, you need one of these.
http://cgi.ebay.com/ebaymotors/AEM-U...Q5fAccessories

I'd also double check to make sure your odometer is recalibrated. But larger tires will net less mileage.
But should be better than your getting.