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Old 10-10-2017, 09:44 PM   #3
700 HP Mach
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Join Date: Nov 2003
Location: Orlando, FL
Posts: 8,190
Re: Why is my Mach1 getting such horrible gas mileage??

does it struggle to start or idle? A blown FRPS (fuel rail pressure sensor) will dump fuel, so much itll contaminate the engine oil but they also usually run pretty rough from my understanding.

how do your spark plugs look? You can have a misfire without it being bad enuogh to trip the CEL but Ford can see it in their tests. Depending on mileage it might be a good idea to just go ahead and put new plugs and coils in it.

I suppose a stuck injector or one thats dumping too much fuel would be a possibility as well but again that usually comes along with a bad idle and other issues.

Does your oil dipstick smell like fuel and as mentioned above is the level higher than fuel (a sign fuel is washing down the cylinders and getting into the oil pan)
03 dsg mach1 - MPR built 9.5:1 motor, D1, cams, ported intake, full exhaust, magnum t56, built rear, E85 etc...

'12 F150 FX2 Supercrew with Ecoboost daily beater
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