nothing to report....it drives just like it did without the conversion except for a little transition stumble (depending on throttle position) from gas to cng which is totally expected. full throttle is no issue...only the pesky nuisance cel is there to remind me that I have CNG or more realistically ... 3 motive means in the car! at this point I am pretty pleased and really want to go on a road trip!

still quite normal...now the hard questions begin...was it worth the 7k to make the air cleaner and reduce my carbon footprint by at least 2/3rds...etc?
more to come....

still not much to report it is still working just fine. I am doing a mileage/c.p.g. test with full fuel and full cng. 3500 lbs of cng cost 9.45!

it has thrown the following codes p2635 p0420 p0430 and p0695.
I have software in my ipod to track all engine parameters and it is really slick to use.
the only code that persists is the low fuel pressure code, when cleared it comes back after about 10 minutes. the others were thrown when the engine was cold (160) or so and when cleared did not come back so far.

more to come.

Jet,
Is there a special App(software) for the ipod that connects to the Tahoe? where can I learn mroe about it?
Thanks
Guss

there is free app named carbonga but it is pretty limited....I bought one called dash command and another called go point they were about $ 50 but very good dash command is very complete and it would totally depend on how complex you want it to be. they will show codes and allow clearing codes but dash command will monitor a lot of different parameters and even has a skid pad and inclinometer as well as a track setting...of course I haven't used those yet but you could transfer it to other cars if you are in to that. you have to buy a cable connector amazon has them it connects the obd to the standard ipod/iphone connector. hope this helps!

did a 150 mile drive today both urban, rural, and freeway. I had my wife drive while I monitored the obd with my ipod and apps.
I began the test by running on gas only until the engine temp reached 200 or so and the thermostat opened. then I turned on the cng and it didn't throw any codes for quite a while. after one shutdown and restart pulling on to the freeway it threw the low fuel pressure code several times which is understandable as the fuel pump is out of the loop. I am looking in to this with a possible solution. otherwise it is a bit lumpy (for me) when it switches back and forth but this is understandable. I have gotten so used to the hybrid smoothness that I guess i'm more sensitive. its still smoother than my friends 2009 gas tahoe!
more to come....

Thanks Jet for the info.

Jet: the pressure code may be a code that needs two consecutive key cycles of failing diagnostics to set.

The loose gas filler cap is one of those.

thanks for the info! that might explain why it is a "pending" cel. haven't had much time to mess with it today other than driving in gas mode until the temp came up then switched to cng without any issues. I am thinking that a re-map of the cng to only work at 190 or so might be worth a try.

thanks again!

still nothing to report..the system works perfectly except for the low fuel pressure CEL that occurs occasionally then resets itself.
my preliminary conclusions are that if you drive 20 to 40 k per year or if you are planning on keeping your car 4 to 6 years it is well worth the effort to look in to this as an option.
the company I used was cngsolutions.net (talk with Daniel) they have been very good to work with so far and I have had NO problems with the conversion aspect of the install. There was an issue with full throttle performance but I believe we got that sorted as well.
CNG where I live is 1.50 GGE and this will pay for itself eventually but the best aspect is that my carbon footprint when running on CNG is 90% less than on fossil gas. The benefits of this far outweigh the costs and your children will benefit the most!
Now we need to make sure the oil and gas companies FAIL in their attempt to get sanctions that will allow them to sell oil to offshore concerns. we should have learned our lesson when we sold out all of our oil reserves to the world at large. It helped move the world forward but it cost us a lot as we had no concept of future reserves....which are now depleted and make us dependent on foreign producers. I guess I am being an isolationist on this but most countries in the world actually have their own CNG reserves....more to come