Im Gettin crappy gas mileage

01OldsAleroGt · 10-31-2008, 06:00 PM

Ok.. heres whats goin on... Im gettin piss as poor gas mileage

120-125 to half a tank

250-275 to a full tank

i floor it only when needed to and i change out plugs, wires, and all that when i got my head's done and LIMG done too.... Plus i did my Fuel Pump also when i bought the car and my FPR did go out before and i swapped it in for another used one outta the J/Y.. and i cleaned it out.. and ran great after that... for about 6-8 months.....

now im gettin crappy gas mileage.... as what i said.. not sure whats up now any ideas... it did sit for about a month to two months.. so im gonna run some injector cleaner.. also.. but mileage wasn't all that hot before that too.. so not sure as of yet.. oh yea.. the only Code my computer kicks on is P0420.. but thats because i punched out my cat... but im gettin a new one soon... but i did have my Evap code go on me.. and i had to replace the Gas Cap... after that now im not sure what else is causing bad fuel economy

jackal2000 · 10-31-2008, 06:51 PM

bank 2 sensor 1, o2 sensor.

black · 11-01-2008, 11:07 AM

try seafoam??

Ryan from Ohio · 11-01-2008, 11:44 AM

I would do seafoam (OR BETTER YET- GM Brand stuff) thru the INTAKE first.

Then I would do the 02 sensor.

Realistically your about where they run at. Could be crappy gas? They test gas quality down there? They dont in Ohio. DO in Michigan and I notice a difference when I get gas in Mich.

01OldsAleroGt · 11-01-2008, 12:40 PM

well i ran basic codes yesturday... pulled up Evap System Leak and Low Catalyst Efficenty.. i know the cat code.. but the Evap code i don't know... but how do i do the Seafoam treatment ?

gonna be hookin her up to a Genesys OTC computer on monday to get the readout on the O2 Sensors and what not

01OldsAleroGt · 11-01-2008, 01:50 PM

ahh ok never mind.. im gonna run seafoam thru the PCV and fuel tank

01OldsAleroGt · 11-02-2008, 12:28 PM

So.. i dove into her last night... found the Evap leak... collapsed hose and the FPR is in working condition... but i really started to think back to my 96 Avenger.... since the backpressure..i know isn't the highest of issues... but i think due to the lack there of cat.... it is causing the back pressure to drop.. which is causing the car to run rich... well. that what my theory is..

gonna be running more tests tomorrow...

zoL · 11-02-2008, 04:40 PM

275 / 14 = 19.6 mpg

That's bad?

cherrington17 · 11-02-2008, 04:50 PM

i get like 24-28.5 mostly highway. depends on where hes driving. if i got 19 hwy, i'd be PISSED.

01OldsAleroGt · 11-02-2008, 04:55 PM

dude.. i was actually gettin anywhere between 325-340 city when i was delivering pizzas

im gettin crappy gas in city and highway.

cherrington17 · 11-02-2008, 05:01 PM

supposedly we're suppose to get 29mpg highway... which is damn near impossible unless its ALL highway (caravan to ASS style)

Ryan from Ohio · 11-02-2008, 05:55 PM

I got a 3100 SFI Buick Century. I took the stock muffler off and put a fart cannon on it. My gas mileage went DOWN.

?

Let me say this again. The GM stuff is WAY WAY WAY WAY better than Sea foam. Advance Auto raised the price of Sea Foam to $9 a can (wasnt even $6 before). The GM stuffs like $10 and is way more potent.

cherrington17 · 11-02-2008, 07:18 PM

got a name, ryan?

Ryan from Ohio · 11-02-2008, 07:56 PM

GM Top End Cleaner Part # 1050002

Comes in a bottle much like Sea Foam.

Google search pwns:

http://www.sytyarchives.com/howto/vi...p&d ir=engine

Im telling you all this. If you think Sea Foam is good, give this stuff a try. Twice as potent!

sk8rsteve2004 · 11-02-2008, 08:05 PM

Quote:

Originally Posted by 01OldsAleroGt

So.. i dove into her last night... found the Evap leak... collapsed hose and the FPR is in working condition... but i really started to think back to my 96 Avenger.... since the backpressure..i know isn't the highest of issues... but i think due to the lack there of cat.... it is causing the back pressure to drop.. which is causing the car to run rich... well. that what my theory is..

gonna be running more tests tomorrow...

Where did you find the EVAP leak? I live in Texas and last week I drove to Mesquite, which is about 40 miles from where I live and got horrible gas mileage. I started on 3/4 of a tank and by time I got home it was about on a 1/4.

The next day, the service engine light came on and that was one of the things that came up that might be the problem. I already replaced the gas cap and the service engine light is still on. I have the 2.2 btw.

01OldsAleroGt · 11-02-2008, 11:01 PM

well check the hoses leading away from the PCV.. thats where i found a collapsed line

[ion] C2 · 11-02-2008, 11:02 PM

Edited, nevermind.

Ryan from Ohio · 11-03-2008, 07:41 AM

? wth?

Cliff8928 · 11-03-2008, 12:57 PM

Quote:

Originally Posted by jackal2000

bank 2 sensor 1, o2 sensor.

There is no bank 2 sensor on any Alero.

You must be referring to Bank 1 Sensor 2.

01OldsAleroGt · 11-03-2008, 11:00 PM

well scanned it today... its all pointing fingers to being catless.... the sprurattic switching of the O2 Sensors... which they are reading both the same due to the punched out cat..is causing the ECU to dump more and more fuel into the system... so i'll def be investing into my cat and exhaust very VERY soon... YAlero.. you'll be gettin your money to ya as soon as i get it !