View Full Version : Noticing increase in fuel consumption

03-13-2009, 10:07 AM

I drive a 1999 Legacy GT and since last weekend, I have noticed an increase in fuel consumption. I filled my tank on Monday and have driven 53km(33miles) since then and I'm already down a quarter tank, or at least that's what my fuel gauge is showing.

We think it might be the mass air flow sensor. Any other ideas on what could be causing this?
I recently hit the 200,000km mark and had a bevy of problems including the head gasket going, oil pan, exhaust, alternator and most recently a broken coil spring. I'm also hearing alot of weird noises from the front wheel area but I'm afraid to go back to my mechanic to get more bad new$.

Any input is appreciated!

03-13-2009, 11:18 AM
Since you didn't post it, I assume there's no CEL (check engine light)? Yes, a sudden mass change in fuel economy can be attributed to a number of the electronic controls. The MAF is one, but that's easy to remove and clean with some spray carb cleaner or non-bleach brake cleaner (green can, not red). When was the last time you changed spark plugs? Is the engine running any different (rougher, less power?). And then there's the possibility that this is a one-time aberation in your fuel gauge (float sensor may be sticky or at fault here). before we worry about seeing the mechanic again, I'd track fuel consumption -vs- mileage for a few cycles (maybe 4+ full tank fills) and see if there's truly a trend or a one-time hiccup.