Hey guyz I recently purchased an H3 and the engine light was on. Went to the local Oreillys and they scanned for codes. It came up with a "P0171" which is a "system too lean (Bank 1)". I bought a bottle of "GUMOUT - Regane Fuel System Cleaner" and being that I was running a bit below a quarter of a tank I added the bottle and filled it up with premium fuel. The light had been on for a few weeks since my purchase. I went a total of about 10 miles on the way home from work and the "engine" light disappeared.

Hopefully this solves the issue. I read that cleaning the MAF sensor also helps but have not got to that point yet. I also ordered a set of E3 spark plugs and will be installing them hopefully this coming weekend.

I will update you guyz to see if this issue is fully resolved. They say fuel injector cleaners never works but I've had results go both ways. I've had it fix issues or burn out fuel pumps.

Only time will tell...

 

Should be fine sounds like an o2 sensors but don't put those crappy spark plugs use oem or iridium tips

 

I brought up changing to E3 plugs and my GM mechanic (former Hummer mechanic) discouraged this. He said that the OEM plugs are the best plugs. He had told me that other Hummers that did the change have had more problems with their coils failing after doing the change. I'm not sure how true any of this is, but I have read in other postings that OEM are the best and stuck with that.

 

Do NOT use those E3 plugs, take them back. They cannot tollerate the coil on plug pack ignition and the electrodes will prematurely fry (I mean well before 10K miles) and your truck will then truely run like crap.

They won't hurt the coils, it is the other way around, the L52 and LLR ignitons burn out the E3s.

 

X2 on the E3 plugs, DO NOT INSTALL THEM! As Doc said, they will burn up very quickly. Stick with the OEM plugs with the correct gap..

 

X3 on the E3's. Cancel that order.
A lot of people have had some very bad experiences with them.

 

Year, model and mileage would help.

Now, as to your code. It can be caused by a simple vacuum leak down stream from the MAF. Make sure your intake is properly in position, and the clamps are snug, then look for a loose or worn hose.

When was the last time you changed (or cleaned if you have an aftermarket) your air filter?

 

Hey guyz thanks for all the replies. I appreciate you guyz looking out for a brother. My H3 is a 2006 with a 3.6, A/T, and OE filter with over 100k so I figured it's time to change the plugs. I guess I'll be cancelling those plugs and getting some different ones.

So should I get the iridium or the OE? i used the E3's on my newly built Pontiac motor and they scream!

BTW, I used the truck this morning again and went for about 23 miles back and forth. The "engine" is still gone so hopefully that will be the end of that.

Again, thanks for all the good info...

 

Sorry, I typo'ed. It's a 3.5.

 

Having the same code come up after changing my plugs, have a feeling I did not put back the intake correctly. Will keep you updated! Great post, comes up top of the list when googling Hummer H3 P0170!