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Discussion Starter #1
I purchased the above car for my son. For what ever reason he getting very low gas mileage.

Has 160k, new spark plugs, air filter, a/f o2 sensor. It drives great to be honest, he gets like 24-25 mpg max he has put 8k on it and never got more. It's an automatic, well one day I finally drove it and found an issue.

While filling it up, it only let's me put like 10 gallons in, have to force the remainder 2+ gallons. He said it's always done that but teenagers lol he never told me.

Can it be a plugged evap canister? Would that affect his MPG?

Any help greatly appriciated!!

Fonzy
 

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Most likely its is the evap system. The charcoal canister could be clogged or maybe the purge valve itself is not opening.

As for the mpg there are quite a few things that it could be. Was the O2 sensor replaced recently or when you first got the car? My first guess is that the O2 sensor is not reading right and the ECU is sending to much fuel. When my dads truck had a one die we went through 2 others to get one that worked properly.

What kind of driving does your son do? Is it mostly highway or city? If its a lot of stop and go I could see it getting down into that range. Or may be hes more of lead foot than you think ?.

Seeing that you already replaced the air filter and spark plugs that rules that out. It could also be the fuel injectors are a bit gummed up. I would run some injector cleaner through and see if it improves at all.

The best thing to do would be to get a scan tool and measure A/F, injector duties and fuel trims. It probably wouldn't take that long for a shop to do a diagnostic on it but getting a scan tool is cheap too so you could do it yourself just with some time and research.
 

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Discussion Starter #3
Yea 02 sensor replaced 1k miles ago with no improvement. Hes not throwing no CEL codes either.

Thanks for the reply
 

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Discussion Starter #5
I just changed the vent tube that seemed it wasnt plugged and replaced the purge valve.
See how it goes
 
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