gas mileage

[MustangLX-5.0]

Your code "P1131 - Lack of upstream Heated Oxygen Sensor switch.Sensor indicates lean,bank 1".

What it means.Your O2 is running extra rich due to an overly lean fuel detection.It's one of two things that could cause this. 1.Your O2 is faulty (most probable cause) or 2.You have one or more stuck or partially working injectors on drivers side.I would replace the sensor.Yo can pick one up at any auto parts store.You may also order one if you can find it cheaper.Bosch or Motorcraft are the only brands you want to use.Anything else cant be trusted.Yeah I know they're not cheap.I had to replace all 4 of mine and spent $150.Should be only a one time investment.

Does your car stumble or misfire when the RPM's start getting up near 2k - 3k ? Is it running fine now?

 

[matt1517]

the rpms never go down, one time a few days back i put it in reverse and the rpms dropped to 500 but didn't die. Going from 3rd to 4th gear when its cold is sometimes a bit slow, i mean it doesn't slip but u do feel a slight bump.


If and when i fix the 02 sensor, and that isnt the prob how much does it cost to replace the (maybe) bad fuel injector? i know u have to take off the air intake and get to the fuel rod. that was on the next page in the haynes manual after the codes.

 

[MustangLX-5.0]

They're not cheap.New,they can go as little as $45 up to $100.Depends on where you get it and what brand name.If your injector is bad,your best off going with a re-man. injector which may only cost you about $25 at rockauto.com.I know your trying to save $$,but if you want guarenteed quality then go with a new one.