Expresscv

2008 express 3500 6 .0 motor code 1174

seems to be pulling this code mostly when 100-110 in southern az and on the hwy
In cooler weather it does not seem to trigger it
no other codes

new plugs, wires, o2 upstream
intake was smoked and do not see a leak, no visible leaks on exhaust manifolds

Slight miss, and a little loss of power
fuel trim on bank 1 was running 3-4% rich compared to bank 2
after o2 change now running 6-7% rich bank 1..??

it is a bank 1 problem so other particular things to check for vacuum leak, possible problems etc on that side please let me know

mountainmanjoe

Which is it ... 1174 or 1774? And you're missing a letter.

Trouble codes are always a letter followed by 4 numbers.

Expresscv

Sorry I typed that right in the title but not the text

it is p1174
fuel trim cylinder balance malfunction

it seems to be kind of a generic code that can mean a lot of things

but definitely my fuel trim is off , bank 1 is always running rich

mountainmanjoe

here you go ...
https://charm.li/Chevy%20Truck/2008/...0Charts/P1174/

Expresscv

Thanks some of that is above my skill level but going to smoke the gas tank/evap system again and the exhaust and then probably have my shop run it on a high end scanner and see what they can come up with
dont think I can read any injector stuff on this one

Triaged

Fuel injector cleaner like Chevron Techron have their uses and this is one of them. Always worth a can or 2 of that and some hard driving "Italian tune-up" style before you have to dig into pulling injectors.

I wonder if you might not have issues in cooler weather because of the different blend of fuel. Summer blend fuel has lots of ethanol in it.

Expresscv

Don't think it is summer fuel related, seeing this going from southern to northern az
it is just more likely to set off the check engine light on the hwy in high temps down south

it is weird that sometimes the check engine light comes on and then sometimes it doesn't but if I scan the code is there
even though I clear it each time

I have a gauge hooked up all the time that scans too and I check it often
been trying to figure out this slight miss for a while

i run probably 70% Chevron fuel and have done the Techron before but that is a good suggestion to do some now
definitely won't hurt

i do think the power is a little better since changing o2 sensors but the fuel trim discrepancy is bigger...??

This code/problem is a pia, too many different things it can be

mountainmanjoe

you shouldn't really have anything plugged into the diagnostics port all the time. Did you try unplugging it?

Uncle Rico

I had the same code on my 2012 Express 4.3L that drove me crazy.
Here's a link to some detailed info regarding the DTC.
https://gsitlc.ext.gm.com/gmspo/mode...%20Engines.pdf

The DTC is also known as P219A on some applications. Mine turned out to be the non-OEM (NTK) upstream O2 sensors that were installed. I had no noticable driveability issues, fuel trims were normal, and the error was not at all intermittent. Your's may be different if that slight miss you're feeling is what's triggering the code. Here's a link to my post for what its worth.
https://chevroletforum.com/forum/exp...75/#post488780

From what I gathered at the time, the engine is monitoring the upstream O2 sensors and through some mathematical magic detecting a bit too much activity on the O2 output which indicates one cylinder on that bank is a bit too lean or rich relative to the others. Of course the computer can't tell which cylinder it is which makes it a pain to track down. I went through similar stuff you are going through - they smoked the intake, ran injector cleaner through it, and looked for vacuum leaks. I feel your pain.