hittman1969

Good morning all....
I have an 06 Silverado and have been stumped by the Check Engine Light for quite some time. Long story short, I had a friend test and came up with 2 codes:


P0449 (Evaporative Emission Vent Control Circuit Intermittent), and
P0442 (Evaporative Emission System Leak Detected - small leak).


Now, I did purchase a new evaporator vent solenoid (have yet to install it) and will also replace the connecting hose. My question is: Will that account for my poor MPGs?? I have been putting in about 10 gals every 2-3 days just running 3 miles back and forth to work. Need input......

Allan In NE

Any time the check engine light is on, the system is just flat 'dumping' fuel in 'er to keep you rolling.

Get your issues resolved and the mileage will improve.

Allan

JPS69OLDS

my 04 silverado doesnt have any lights on but get 10mpg which is very bad just wish i could get it back to what my 96 1/2ton got aka 16mpg

'03 Heavy Chevy

Your engine size (along with properly operating parts) and gear ratio are big factors in your gas mileage. The short drive to your work is a factor too. Sounds like your truck spends more effort moving and stopping.

My '03 2500HD 4 spd transmisson gets 8 mpg in the city, 13 on the highway, so you are lucky if you get better than that.

JPS69OLDS

the weird thing is with my truck it doesnt seem to matter if it is in town or high way it is the same, 10mpg and its in over drive all the time to boot. i just wish GM retard engineers didnt make the fuel filter and fuel pump in the same unit. cause that would be the 1st thing i would change to see if it help my gas mileage out any.

all ready did plugs which didnt help at all and spark plug wires cost to much for how short they are, beside i dont see that helping out anyways. kind of like a rotor and cap but again engineers mess that up too.

seems the gm engineers and designers got more and more dumb over the years. just wish my chevy dealer would have offered me a warranty package when i got this used POS cause they would have it longer then i do for the repairs it needs. which will all most make it a new truck after they fixed it all...

'03 Heavy Chevy

Yours doesn't have an inline filter located on the frame under the truck near (under) the driver's door?

That's where mine is on my 2500HD. My Z71 had one in the same area.

There is a filter screen on the fuel pump but chances are that isn't plugged up unless you got some bad gas somewhere and if that happened you would have had more than just a low MPG issue.

I hear ya about changing some of that stuff. I don't see a difference either, but the one thing I know is replacing the normal parts (like plugs and wires, filters, etc.) won't be the reason my truck leaves me stranded somewhere wishing I had changed them. LOL

I bought the duralast brand plug wires at autozone. At the time that was the cheapest I could get when I was working on my truck.

JPS69OLDS

i havent looked but when i went to autozone and ask about the fuel filter it didnt come up with any just that it was part of the fuel pump. i figure well i would go and ask at the dealer and they said to that the only fuel filter was on the fuel pump and it was like $500 or so. my old 96 chevy truck wasnt like this truck at all. it had the old fashion stuff that can be replaced which was simple. i am thinking about the cats and maybe do something with them but that is a major job just getting to them..

'03 Heavy Chevy

If yours is the gas-hybrid model then there isn't an inline fuel filter. If its other than gas-hybrid then it has an inline filter. If the later is the case then the store employee is looking up the wrong vehicle. Whenever I need to go to Autozone, I look up the part number first for several reasons....I know what part I need so when I get to the store I tell the # and they get the part and I'm gone (no more of a wait than necessary), I verify which store has the part so I don't drive everywhere looking for it, and if anyone is wrong about the part I can only be mad at myself

Here is the Fram catalog link. You can punch in your truck info and get the filter # for your truck.

FRAM - Application Look-up

I get the Fram # and pick up my filters at Walmart.....they are consistently the cheapest around.

therewolf

My '04 -2500HD-6.0 doesn't have an inline filter, either.

Oh, they sell one at the parts store, but a lot of trucks just

came with the sock filter on the pump in the tank.


Tire inflation is very important for good MPG. Check your

RPO codes for your gear ratio, anything higher than 342s

is going to cost you. Lift? 33s? Hogged out DE? It's all going to cost you MPGs.

Guys, pickup trucks are undeniably great, but we're talking

about a vehicle with the aerodynamics of a cinder-block

here.

Consider new shocks, changing your tranny filter, and tune up.

You'll gain dribs and drabs of MPG back, but you keep working at

it, and with some careful driving, you can improve your mileage

by a respectable amount.

'03 Heavy Chevy

LOL very true!