Help, please, for a total newb?

[2k-Sierra]

I have a 2K Sierra with a 5.3 with plenty of issues since I'm not certain of how to set this up. I'll preface this by saying I've been a mechanic and a hot rodder for 50+ years and am still old school. But, I can still learn. That being said, I picked this truck up from a guy who was pretty clueless, too, and he put a tune in it that allows it to run, but very poorly. Belwo are the engine specs:

Eaton 4:10 posi
built 4L60E transmission with 3k stall.
BTR stage3 cam with btr pushrods and jegs ls7 lifters,
long tube 1 7/8 headers with race pack mufflers and 3" true dual from headers back.

Now, I have a sneaking hunch that he tuned this with the EGR valve extremely loose and dangling. It's running pig fat and won't idle until it's warm. The shift points are way off, and the speedo works, but when coming to a stop, the truck stops and the speedo moves to zero very slowly which keeps the idle up and pulling against the brakes.

First question: The truck came with 4 02 sensors, he has two of them plugged in. There are no CATS so what should I do with, and how do I use the 02 sensors? I want to be sure the hardware is connected properly before I ask about the tuning he did. I did read the module and saved the tune. Can someone point me in the right direction of what to do with 02 sensors and the like?

TIA,

Greg

[5FDP]

It only requires two front o2 sensors to function, if you wanted to run o2 sensors anyway. The rear sensors can be removed and if there are no cats, they are useless anyway. They can be turned off in the calibration as well. Set all the rear o2 sensor codes, the cat efficiency codes and the cat over temp protection to be disabled. The codes are the done in the engine diags DTC page. Set them all to no error reported with the SES box unchecked.

What headers even come with an EGR hookup? I haven't see those kind in forever because everyone just deletes the EGR.


Make sure the gear ratio and tire size is correct in the tune. Check the gear/tire wizard in the edit tab to make sure that is right.

It's going to need a lot of tuning for that camshaft and the other mods to make it run good. It will likely need larger fuel injectors too because that camshaft will make power well beyond 6,000rpm.

[2k-Sierra]

Excellent info and much appreciated. I will disable all the 02 sensors and use the bung for a wide band. There are no EGR connections, but he just cut the hose off and left it open. Plus, the entire valve was loose and sucking air into the manifold, I would assume. Since I gasketed it and tightened the bolts it runs extremely fat. Went thru about 50 bucks in fuel in about 75 or so miles. I did use the calibration tool and have the proper 4.10 ratio and tire size. But the speedo is strange as if I stop quickly, the needle slowly floats to zero. That keeps the rolling idle pulling against the brakes until the speedo drops. I'll attach the tune the guy has in it if it will help. I just need a little guidance to know the proper verbiage and I'll be learning quickly.