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Low mpg on my Ranger

My '99 Ranger has 137,000 miles and otherwise in pretty good condition. My gas mileage is down to about 14 mpg and take off is slower. My trusted mechanic thinks it’s probably the catalytic converter that runs about $1600 to repair. Anyone else with this problem or other ideas. Is it worth fixing or time for a new truck?

“probably” is a guess, not a diagnosis. Has he done any diagnosis?

I agree with “the same”

It’s not the catalytic converter. Your vehicle has the OBDII engine management system, and if there were any problem with the catalytic converter the Check Engine light would be on with a catalytic converter code stored in the computer.

When fuel mileage drops off all of a sudden you want to check things that can cause this without a Check Engine light. Things like a stuck open thermostat or a coolant temperature sensor for the computer sending false signals. Either of these can cause a drop in fuel mileage without the Check Engine light coming on.


My engine light has been on about 4 years…after a couple attempts to fix it with no success I gave up bringing it back. The drop in mileage has been more recent.

My mechanic looked it over pretty well, including test driving, computer etc.

“My engine light has been on about 4 years.”

Well, there’s your problem. What was the code that was pulled 4 years ago? What are the codes today?

That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here.

if ti’s been on for 4 years, I doubt ANY codes have been read at all, especially if his “mechanic” ‘thinks’ he ‘probably’ needs a new catalytic converter.

You don’t need a new truck, you need a new, competent, mechanic. And good luck selling it with the CEL lit and you telling them it’s been on for 4 years

Generally the CEL light and error codes do not point to a specific part to replace.
This is one of the rare cases the light points directly to what needs replacing (the mechanic).

If only there were a code for that :wink:

BTW sometimes when the CEL comes on it’s because of a problem with a sensor related to air/fuel management. When this happens the ECU puts the car in limp-home mode, which often means running rich. Running rich = crappy gas mileage.

A CEL should not be ignored. If a mechanic can’t fix the problem, then your mechanic is a dink and you need a new one.