Hi Scotty, big fan..I bought a 2006 Hummer H3 w 133,000miles for 6200. About a month after I got it, things started happening, I had to replace my front 02 sensor, then somehow, I got 5 gallons of water in my tank. I replaced fuel pump, coils, sparkplugs, and I am getting a really rough idol to the point where it dies, or i push my foot completely down on the gas and nothing happens. I'm getting a P0300 code, that's it. However the downstream 02 sensor is bad, and the new one is plugged in but not in the muffler..My obd says i have no engine mis, but I did notice that when i clear my dtc codes, i'm able to rev my enging breifly...To go in reverse, I have to pump the gas, and to go forward it is sluggish, but when it kicks in she flys, no banging,clanking,sputtering from engine? I don't know...but I'm wondering if clearing the obd2 scarnner and it revs fine means anything....
Unfortunately, 2006 H3 was the first year of the H3’s but also the worst year with so many issues, the biggest being engine and electrical problems. If it were me, I’d get rid of it as it can quickly become a money pit with one problem after another as you are finding out.
https://www.carcomplaints.com/Hummer/H3/
Besides electronic stuff, the transmission of those cars is horrendous. I totally agree with @DayWalker. Get rid off f the car if you value your time and money.
