I have a 97 with a 5.4 and 28000 miles. The engine light came on and I took it to the dealer. O2 sensor was out and changed. The light came on again. Is there a likelihood the others would go out at the same time? Also, the gas milage is about 12. I get about 200 +/- miles to a tank and the performance seems not like it should be. It will also idles rough at times. Any help would be greatly appreciated. Thanks

 

That's an extremely low mileage for that year, do you know for a fact that mileage is correct? Did you buy the truck new, or second hand?

Please post some more info, what has been done to the truck, what service has it recieved that you know of.

Something definitly sounds amiss.

I don't know how many gallons the fuel tank holds in your truck, but if it's the same as mine (95 litres) you should at the very least squeeze 300 miles out of a tank.

Good Luck

 

I'm getting 13mpg in my '98 F150 with 46k miles. Ofcourse I do mainly city driving. I get about 300 miles to the tank.

 

I get about 13 to 13.5 mpg also, but 90% of my driving is all city.

 

I just returned from Auto Zone and the computer had two codes. One was 1151 and the other stated that bank #2 was running too lean. Any ideas what the 1151 code is? Also, could there be a bad O2 sensor on bank 2. I just replaced one on bank #1.

 

HI!... When it comes to replacing 02 sensors you should ALWAYS replace both left and right sides at the same time. This is a must for the upstream 02 sensors. I have over 330H.P (flywheel) and 4.10 gears and I can go 735KMS on a tank of gas. That's about 450 miles.

 

I hate you Neel!

 

I have a 2002 F150 with a 5.4, it only has 4500 miles on it and the stinkin' service engine soon light came on today. I called my service dept and they said that it might be an O2 sensor. Like you I am getting cruddy gas mileage, about 10-13 mpg. I have a 25 gal tank I think and right now I have less and a quarter of a tank left and have gone only 180 miles, what the heck? I find it unusual though that I would be having any lights come on this early in the truck's life.

 

I had two GM products that were new before this truck and had the O2 sensors went out in less than 10,000 miles.

 

What kinda gas are you using? Are you using any type of additive in the gas?

Got 97k on mine........ use only Texaco or Chevron. Never put an additive in the tank either.

 

Is it possible to have a faulty o2 sensor, and not know about it?

Anyone?

 

Habibi,

In a perfect world, No. But the correct answer is not likely. The PCM measures the O2 sensor output. The variance in voltage, because of the change of the O2 content in the exhaust, is what the PCM looks at. When it varies past a given value the PCM sets a code to tell you it has failed. Also the PCM is constantly switching from a lean to a rich A/F ratio. It sees a lean condition and sets a rich correction and vice versa. When the O2 sensor stops switching or doesn't switch fast enough it also sets a code. So if you want to spend $$$ to replace a good sensor, go ahead. A lot of people will argue that you should. If you want to milk every last bit of power or fuel economy out of your truck then go ahead and change them.

Regards

Jean Marc Chartier

 

It "could" possibly be a coil (my friend had one go bad) or an injector. Both simple fixes but semi tricky to diagnose. The easiest way to diagnose that I know of is to remove the connectors one by one at a time with the engine running. NOW THE ONLY COILS YOU CAN UNPLUG WITH IT RUNNING IS COIL ON PLUG. WHERE YOU HAVE ONE COIL FOR EACH INDIVIDUAL CYLINDER. If the sound of the engine changes and or it vibrates worse that component is likely good. Because the injector or coil is now not working. If there is no change there is a good posibility that the particular component is not functioning and possibly the bad part. A bad injector would indicate lean because that cylinder is only pumping air. Sometimes a bad coil will show lean because the oxygen is not being consumed durring the firing of the fuel/air charge. If there is more oxygen, lean condition. Both would contribute to poor mileage because a cylinder would not be producing any power and the other cylinders would have to work harder to move the vehicle at the same rate. This diagnosis procedure would work for any fuel injector except CFI or throttle body injection. And on any coil on plug application. IF it is a coil or injector, they are both reletively quick easy fixes.
Darin

 

Thanks Jean Marc.

 

Thanks for all the help!