Ross Reynolds

2007.5 Silverado LTZ Crew Cab 5.3 NNBS (GMT900) Lean both banks, no external air leaks found and averaging 25% fuel trim on each bank. I’m Ross and I’m a parts changer. (Hi Ross!!!) I’m ashamed for not figuring this out but I’m stuck really needing some help. This started about 6 months after a black bear tune and AFM delete. I love the tune and realize this not the problem, but nonetheless spent several weeks trying to teach myself how to diagnose fuel trims, tried several things like cleaning MAF and throttle body, spraying starter fluid around joints to look for leaks, etc. . Next I found a local reputable shop and let them spend two weeks smoking the intake system multiple times while trying to figure it out, (and me renting a truck) they changed a couple of exhaust o2 sensors, and gave it back to me, not fixed. I spent more at another spot that couldn’t figure it out either. I try to not be an idiot, these were both shops with great diagnostic reviews, I have not gone to the dealer for this but only because I can’t afford for them to lie to me too. This leads me to deciding, well I love the truck, it’s paid off, it runs like a top, clean, no visible smoke, no leaks, I’ll start methodically going through each system if I have to and replace things that I have learned are usually the problem in order. I can do it myself, I’m a contractor and a struggling family man with no dough, so my daily driver needs to be ready if I need anything. Next, the part replacement started and now that I have replaced (and correctly torqued in pattern when necessary) everything, the numbers are slightly better, but still ridiculous, setting lean codes and I’m sure it’s tripping the brake/traction control system as well. No other problems, no misfires known of, etc. . Now I bought the truck with 100k, started a mobile1 synthetic oil regimen, have changed all serviceable fluids, blah blah blah. I’m going to attach a list of most things that I have done/changed. Everything I have bought has been stock, mainly ACdelco. Some of these things were not for lean issue but I try to keep a list so I can remember what and when I changed something. I’ve decided the problem must be internal but I have the AFM deleted so it shouldn’t be lifters right? Well here’s the list, please help. Silverado parts replaced 97,****** A. Bought truck, started 5k oil changes with Mobil1 full synthetic 150,****** A. Front wheel hubs, suspension joints and brake switch attached to pedal arm. B. Fluids (tranny 4 qt pumped from top, coolant, rear end, brake fluid, and power steering. C. Reengineered Dorman valve cover due to excessive oil consumption D. Kenwood touchscreen head unit with Nav, HD radio, Apple CarPlay, Android, full Bluetooth with OEM steering wheel functionality, rear seat controls and OnStar still working like new. E. Dash cam (matched Kenwood) for fighting traffic tickets and dumb-ass drivers. F. Rear view full capability camera (matched Kenwood) mounted inside square steel tube located directly above receiver tube for trailer hitch. (Makes hooking up trailers by yourself easier than EVER!) G. Sport tune by Black Bear (California) w/ AFM delete 165,****** A. Fuel pump B. Carbon filter C. Vapor canister solenoid D. Throttle body E. Fuel cap F. MAP sensor G. MAF sensor H. Master cylinder I. Injectors professionally bench cleaned J. Pre and post cat o2 sensors K. AGM battery L. Serpentine belt and tensioner pulley M. PCV hose N. Intake manifold gasket 185,****** A. Professional through fuel rail carbon clean B. Power brake vacuum booster C. Fuel vapor purge valve D. Active brake control sensor E. Big alternator (I think it’s the 160 amp) F. Active brake control valve (pump) assembly and module 193,****** A. Intake manifold

Now I’m not a pro, (as in do mobile electronics for a living) but I have worked on all my own stuff since I was a kid. It took me 4-5 hours and a call to Crutchfield but they were Johnnie on the spot with their customer/technical service and I have been happy ever since. If anyone is interested I can take some photos tomorrow, I tried a minute ago but it’s too dark and they are not coming out very well. I realize this may sound like an advertisement for Crutchfield but it’s not. I couldn’t afford them as a kid but as a faithful current customer, they are a great choice in this space. If you want to go with a dash cam and not upgrade the head unit, you could still remove the drivers A pillar cover and drop the front drivers portion of the headliner, in order to run keyed power from the fuse box and then mount the camera like mine. Most of them come with removable storage so you really don’t need it attached to the head unit. In this case (if you ever had a problem) remove the data card from the camera and view or download to a computer via usb with a card reader.

Sure you can. I got my gmt900 07 crew ltz about 4 1/2 years ago with 99k. I promptly replaced the head unit with a Kenwood touchscreen system. I got a secondary controller that allows me to still have OnStar and my steering wheel controls, but now I also have Apple CarPlay, Serious XM, HD radio, Navigation, etc. . At the same time I added back-up and dash cameras (also Kenwood). I got the whole package from Crutchfield in VA with ready made (soldered) wiring harnesses, a dash install kit and custom install directions for my truck. It was all about $1000, and then I installed myself.