If it was my rig, you have received a wealth of information from Hummerz, Gavin. clsimmon, sam & others- the knowledge these guys have on these particular rigs is extremely valuable. I would start with their advice first. Get the Catalytic converters off your mind - they are not causing those codes. As far as ground issues- they can occur at any time. The TAC module / associated wiring & the seafoam procedure would be where I would start.......

 

Btw, my oem factory assembly line installed 2006 cats are still efficient!

 

I will be following everyone's advice, I have a Nano w/ TECH2 Win ordered. I just haven't been back on the H2 as was busy with other duties around here as something always comes up. Got to get a couple things done on a tractor before H2 can continue. Plus Wednesday, I go into hunting mode till next Monday and should have Nano by then. But then we have Thanksgiving week and our daughter, sil and granddaughter come up from Knoxville so not a lot will get accomplished, except I plan to have him help me get hood off. We will at least look at it thru Tech2 though. I definitely respect everyone's input and appreciate it. It won't be wasted. Just things don't move as fast anymore around here. I have been reading Tech2 manual, watching vids and learning on fuel trims etc each evening so I'm more prepared when this gets serious. Thanks again and yes I appreciate your time effort and knowledge. Roy

 

Can attest. As cool as the H2's hood is. It is not one bit functional and make simple things super difficult. Wish you a good thanksgiving and good luck with the nano lol. Some people's experience is not as good as others, but once you figure it out, its well worth it.

 

Hope everyone is poised for a great Thanksgiving with family and/or friends. Be safe in travels and deep frying the bird if that’s the plan.


Well, I got the Nano and software yesterday and no issues getting it all loaded last night on Win7. Plugged in earlier and read DTC, went to mis-fire section and 1 & 3 where the worse with 3 showing accumulated at 18,000+ but it started throwing disconnect error repeatedly but would reconnect instantly in the beginning. Went to crank relearn to try it for hell of it, fuel shutoff was said it should be 4000 for v8 but it will go to 6000, I continued with step to cycle ignition and it just keeps giving lost connection. So, I abandoned that attempt. Went back to just looking live data and just keeps losing connection and won't reconnect without starting over.
Red light on Nano stays steady with blue light flashing. Anyone had this issue?

Since last post while waiting for Nano to arrive, I checked grounds with test light and they all had good connections. I removed throttle body and MAF, cleaned them both good. MAF looked ok but don't believe that means anything but cleaned the MAF with MAF quality cleaner and cleaned TB with gumout carb spray. It was terrible. What I could see in the intake looked ok but couldn't see far and not like the TB. So, I went to the shop and talked to manager that did the Valvoline induction cleaning and asked as to why the TB wasn't clean if they did actually do the induction cleaning as I paid for. He didn't have a good answer other than he saw them hook it up and start it but said they should have removed the TB and manually cleaned it as I did. He went to lunch after they hooked up the Valvoline machine. The induction cleaning system is after the TB he said. Previously they had done what I thought was quality work for me on the other stuff I've had done on the H2 and another truck. Since I have spent in excess of 10k with them he will hit it again to keep me happy if I think it needs it as I had another bitch where they told me crossmember bushing was shot but when I cleaned and painted the frame 2 months ago I dropped it and it is near perfect, just had a lot of buildup around it so how could they even see it to say it was bad. So, I got the seafoam cleaner and another bottle for in the tank and did it myself. As stated earlier I keep some in the tank regularly with Marine ethanol treatment Stabil as well.

Plan is to try and continue to diagnose further if when I can figure out why the Nano keeps losing connection. I will probably end up pulling the intake and see with my eyes the valve stems etc and replace knock sensors while in there. Knock code has never shown and when the Nano was connected, I saw zero knock count, so another reason to avoid pulling intake at this time. I sprayed around the intake with flammable brake cleaner and saw no change in my fuel trims, so I’m inclined to think I have a good gasket seal. I'd really like to do all I can before taking it down to get closer and/ or correct the mis-fires saving the sticky valves theory as last resort if I can.

I hooked my ZR11 back up and it has no connection issue watching live data. I’m stumped if it is hardware or software with the Nano as to why it keeps kicking out? Appreciate any info with your Nano/Tech2win experiences and if you have seen this issue.

 

check if your intake manifold bolts need to be re-torqued especially on cylinder 1/3 drivers side.

 

Ok I will check them.

 

i think there was a GM tsb on bad intake manifold gaskets

 

Any sort of aftermarket electronics installed like stereo, alarm, remote start, etc? Many of those tie into the data lines and can cause lots of chatter on the network making scan tools freak out. If so disconnect power to the aftermarket stuff would be a thing to try. Possibly also connect external power to the Nano (if those have that option, I know the Tech2 does).

Misfires could be a lot of things for sure. Another I've run into many times on GM engines is someone prior had installed new spark plugs like Bosch and it runs like garbage after a while. Pop genuine ACDelco ones it and that fixed them. Failing knock sensors could of course be the issue as well. If you do replace them, also only use genuine ACDelco ones - the others are mostly all garbage that dont last long and replace the knock sensor harness when in there doing them. Not a terrible project to do but not very fun either, particularly on the H2 since you can only get to it from the sides. Intake manifold gaskets can also be a problem but you already sprayed around that so yours is probably okay. But your misses are worst on 1 & 3 which are the front two driver side cylinders so possibly that it might be the intake gasket but on the underside....

 

I'm original owner and no aftermarket add on's or swap outs to mess with power/ signal interference. Had new ACDelco plugs and wires and made no improvement. Its still a noticeable miss but the intake side cleaning I detailed did smooth it out a bit. Correct it could still be intake on side and the brake cleaner isn't getting picked up under there, I did soak it pretty good to give it every chance to be sucked in. Nano not setup that I can tell for a different power supply, but my ZR11 has no issue if it was power lacking from port it I would think effect any tool connected.