I think I can load it but I want to ask first. I also sent a email to VMP to ask but I dont know how long it will take for a reply. Justin sent me a xcal3 with a 87 tow 87 mileage and a 93 perf tune in it. I had told him that the truck would have the GOTs mod, maggi high flow cats, maggi 18" di/do muffler, and dual tips. Well I am about to pick up the truck from the mechanic that did my spark plugs and was also going to install the exhaust but his pipe bender went out. So I will have to wait about a week to get the exhaust done and I have not done the gots mod yet. So can I still load the tunes in the stock truck? I would think I can...I thought Justin had told me those mods wouldnt really effect the tune. It seems that I have read that the gots mod doesnt and theres lots of people that have exhaust stuff with no tune. So I should be ok right??

Also side note...87oct is in the gas tank now...do i have to run 93 through it a few times before I load the 93oct tune or would running the 87 down to the low gas light and then a full tank of 93oct be good enough?

Thanks

 

Yes, load one up. Just match your octane with the tune.

 

Thats what I thought...I was going to do the 87 millage tune first since im not towing anything. What do you think about going from 87 to the 93. Can I run 87 to the low gas light then a full tank of 93 then load 93oct tune or should I run 87 down to low gas light then do 1/2 tank of 93 to low gas light then a full tank of 93 then load 93 tune?

 

I have never had a problem running it till the light came on, filling it with 93 and then loading the tune.

 

Cool...thanks...if it blows its on you and you owe me a motor.


juuuuusssst kidding....totally kidding lol.

 

If you have a 30 gal tank and run it to the low fuel light, you'll have about 5 gals left in the tank. If you fill with 93 octane, this is the resulting octane value in the tank:92 octane should be fine for a performance tune. But, don't switch tunes until you get the 87 octane gas out of the gas lines (about 5-10 miles after fillup).

- Jack

 

Exactly what I did with no issues - enjoy.

 

Ok well I picked up the truck (spark plug change @ 144k)...drove it for a few miles....loaded the 87 oct and smiled. I tried to burn the fuel until the light came on...but...I thought I might have been close enough. The fuel gauge needle was hovering just above the E but no light yet. So I tanked it up with 93 and loaded the 93 tune in while it was filling. Left the gas station and it was pinging pretty bad if I gave it more than a little gas. So I pulled in a parking lot right away and put the 87 tune back in. I didnt know about the driving 5-10miles to clear the lines so maybe that was it. I put about 23 gal in...so it might be close...might have to burn a whole tank before I can enjoy the other tune...servs me right for not waiting for the light lol. I might try again after I drive a few more miles....

 

I suspect its due to the 87 still being in the lines. Give it a few miles and try again, I suspect you will be fine then. Smart move going back to the 87 tune before damage was done.

 

Yeah it was pretty obvious something was not right...any more than a tiny bit of throttle would result in what sounded like marbles in a tin can. So I drove it slow and parked it.

 

All good now...87 left in the fuel lines!

 

I usually figure on running 2 tanks before running the higher octane tune....

 

 

these trucks run on a returnless fuel lines?

 

The 04+ does - that's why you have a FPDM.