It feels like a different truck!

[chongo]

This past saturday I climbed under the truck and Ill be damned if my exhaust didn't fall off Luckily, I had a replacement in the garage. After some cussing and some work with the hammer I "repaired" my exhaust. Holy smokes - the difference is huge! I am running an SCT with KEM's 250 - I took my pipes to have the sensor bungs welded and had Mike write the tune to bypass the sensors - made the "fix" quite a bit easier. I am lucky that my old man has done well for himself and likes his sports cars - I have driven Vipers and ZO6's - he is now on a ZR1 - I say this for this comparison: this 8500 pound truck is more fun than that ZR1 - a truck this big/heavy should not be able to move like it does now.

I have no idea on the mileage as of yet - I need to keep my foot out of it
I'll be honest though - I do get a little nervous each time I put my foot in it - slightly nervous about HG but really just in disbelief that these trucks can make such big power off of a "simple" tune.

Now, I do have a few questions for those that are tuned.
-Idle - mine is at about 900RPM's - is that normal because it wears my right leg out keeping my foot on the break at a light.
- I have always referred to it as the "engine rollover" when you shut the truck off it feels like the motor is rolling in the engine bay - I don't have that anymore it shuts off like a gasser - doesn't bother me either way.
- When using CC set at 40 -45 it will not maintain a constant RPM but accelerate then RPM's fall off like they would when you take your foot off the throttle then it will immediatley rev back up to maintain spedd - on a perfectly flat road it is not a problem but those are few most roads have some sort of incline to it so the truck is constantly revving up and letting off -does that make sense?

Last thing is my boost gauge - it constantly reads 1-2lbs - it never rests on the "0" line even at idle - I am guessing that has something to do with the idle being 900 RPM's?

Other than those issues the tune is great and I am hoping when I can keep my foot out of it that I see an increase in mpg's - we shall see.

[HoleShot08]

Yes the idle is hi. Mine is around 650-700. The deal with the RPMs is the T/C is not locked up. I think with the 250 it locks around 50 mph. Talk to Mike and see if he can change it. My KEM 310 locks up between 43 & 45 when taking it easy. The boost gage always reads 1-2 lbs. boost. Do you have a cold air intake? If not you mite want to get one the S & B is real good for the money and you will pick up 1-2 mpg. Ask Mike about that idle.
-Mike

[chongo]

We are both scratching our heads at this point - downloaded the SCT performance tune - same high idle - I plugged in all sensors - did not/can not install them in the exhaust pipe but I plugged them in and no difference in idle. Ill have to wait and see what Mike thinks.

I do need to get a CAI - I hate having to constantly reset the air filter guage - and it's surprising how little throttle it takes to set that thing off.

Edit: Putting the truck back to stock and I am going to take it in and see if the dealer can find anything wrong. This sucks

[HoleShot08]

Yes somethings not right. Thats a pain but it is best thing to do. After its back to stock check for codes and clear everything then wait for a regen for you take it in. That way if they run a scan everything looks good. If they ask any questions tell them you unhooked the batteries to clen them.
-Mike

[chongo]

I am wondering why it would idle high after tuning but I can return to stock tune with deletes in place and start it and it idles like stock - 600-650 range?

I am just trying to exhaust all efforts before doing the wrench work again.

[chongo]

Nevermind - returning to stock is a PITA that flange forward of the cat is a pain to get to.

[Matt@SCT]

Originally Posted by chongo

Nevermind - returning to stock is a PITA that flange forward of the cat is a pain to get to.

Are the sensors hooked back in the pipe when you returned it back to stock?

[chongo]

Nope - which was the problem - I talked to JR and he helped me out.

[Matt@SCT]

I am glad he got you all taken care of.