I'm getting less then 160 to the tank. Insane right?!
Problem I having w cat;
Robbed milage. 8mpg or less
Insane nasty rattling which I thought was bolts from heat shield and skid plate due to missing bolts. Replaced em but rattling got worse. It rattles insanely under passenger side in that cat. (Not from headers cat)
Check engine light came on have me reading P0420 Cat bank 1.
What I've done since I've started to experience this problem store the light came on;
New k&n filter
New spark plugs
Synthetic oil etc
I recently bought new cat from dealership paid almost 800 bucks for which looked used came in no box or wrap. Already all rusty and looks like they grabbed it from the garage spare parts. Only 1 yr warrentee. Wtf?
To remove this cat from under passenger side only 3 bolts connecting to header cat in triangle formation. The top bolt at peek of triangle bracket is IMPOSSIBLE TO GET TO. then theirs two bolts towards the mufflers. I broke 2 of 4 bolts I've removed in less then 30 min. (I weigh less then 140lbs and I'm braking hummer bolts off? Hmm pretty cheap ****). The top bolt at that triangle bracket is not coming off any I'm only stripping it. Impact guns are too fat to fit. Wtf it won't budge but rest came off no problems. I don't care if it breaks off, I'll replace it but won't budge grrrr. I've spent over 6 hrs on this one bolt and about to take it in to he removed but of course it's a Sunday so a day lost now so I'm on here trying for some help. Please give me ideas so I can fix this piece of **** and get rid of it. I wasted too much money into it an just wanna be done with it. All Chevy dealerships don't know anything about HUMMERS. I should become a tech due to so much sit I've already replaced on this in less then one year of owning.
I'm also having my theft deterrent system shut my fuel lines off for 10 min until I can restart the H3. (Read in H3 Manuel) Happens at least twice a fill up. Dealership says bad connection from key to ignition receiver and try other key. Still same prob. They also mentioned aftermarket alarm to bypass deterrent system. So stupid. Why does the 2006's have problems. Should be recalled. I hear so many people with this same deterrent problem thinking it misfire but you have a code reading for that. Totally different. I hear they spend hundreds to dealership to fix this problem but waste of money because the dealership have no idea what they are doin on HUMMERS. It took em 3 days to replace my tail lights lol. Come'on really? **** the dealership garage. Please help me thank you

 

I MOVED this thread .............. just because you thought it up does not make it an FAQ.

 

I don't think Hummers are for you. All straight forward fixes, and can save some dough by doing a little searching. Sorry about your experience. I know it's hard finding a good hummer tech too, and if you go to a lot of places they don't know what they are doing. But honestly, every vehicle has issues. Good luck with everything.