wilshire37

The range keeps it in V-8 mode so all the lifters are working all the time. Non functioning lifters would give running issues which I have none of. These codes are lean codes so I'm figuring unmetered air is entering after the MAF sensor somewhere. My next step I guess would be to have the engine smoked. thanks for the responses.

So I have an odd situation on my truck. I use a Range technologies device to keep the engine in V-8 mode, I have to remove it and let the computer reset to get my inspection sticker. After doing this I got a CEL with P0171 and P0174( lean condition bank 1 and 2) I cleared the light and drove the truck but it came back on. Plugged the Range device back in and no CEL. The truck runs excellent no misfires, hissing, stumbling, bad gas mileage...nothing. I cleaned the MAF and even installed a new one I had(GM) but light came back on. Checked all connections, lines, gas/oil cap, dipstick fully seated, no exhaust leaks...nada. I 'm leaning towards a possible PCV valve? Any ideas? Thank You in advance.

So here is the update, on the intake where you put the gasket to seal the supercharger they have dowel type locators installed. one of these was keeping the s/c from fully sealing even though it looked flush(gasket was basically floating around and got damaged). Obviously this caused a vaccum leak. waiting on new gasket and corrected the dowel issue. Will get back soon to let everyoneknow if this solves my main problem. what year LT4 PLUGS did you use jaychevy? and what gap? thx for everyone's input

ok thanks for the info,I also emailed your company with some other questions just waiting to hear back

I am waiting on SLPTUNE to get back to me. I am going to contact black bear and see if they can help me out if slp won't. Anyone know if I can use my sct tuner with them?

I'm running new factory plugs and the truck ran like a top before this.

My idle on a cold start is normal, then as it warms up it drops to between 350 and 500 rpm. It then starts popping through intake and out the tailpipe like a bad maf. So I put a factory replacement in(AC Delco) and nothing changed. So I unplugged the maf and it idles perfectly until you touch the gas then dies and the CEL is present for the unplugged maf codes. I got it on the highway and it ran pretty good but under a certain speed decelerating it is awful. The truck has only 27462 miles on it. The only upgrades were MSD plug wires, fresh plugs, AFE coldair intake, gibson shorty headers and a magna-flo cat back exhaust. I also use a range technologies plug-in the OBD to keep it in V-8 mode. The truck is meticulously maintained since new. I did double check everything and it all seems tight. Sometimes it will stall and throw codes for the top o2 sensors having low voltage which makes sense because the idle will bottom out and stall. SLP support told me to email the tune guys and ask for a new tune and describe whats happening but no one is getting back to me. I will look into a local tuner, thanks for the reply and I will update if I figure it out.

What is that you have mounted on the firewall? Did you add that? I am extremely unhappy with my tvs 1900 in my 2014 sierra, I can't drive it as it won't idle properly. They are not being helpful at SLP and I don't know who to turn to. I am at the point of unistalling it until I find someone who can help me.

Yes, I preloaded the tune per the instructions and a tank full of 93 which I always use. The truck won't idle and pops through intake and tailpipe like a bad maf. So I bought a new factory maf and no change in running. Unplugged maf then started the truck, guess what? The truck idled normally until I gave it some gas then it died like it should. I think they gave me a crappy tune. Getting on the help line tomorrow but I'm at the point where i might take it off if they give me the run around.

I have justed installed a tvs 1900 supercharger on my 2014 sierra 5.3L. Very easy to install but I am having a major running issue.