Lean Fuel Mixture

[E'sBird]

Wow, my T-Bird has developed a lot of problems. Now I am getting a 171 and 174 code, lean fuel mixture both banks. The car idles great, runs fine, but about an hour or so, it throws codes 171, and 174. I have put a bottle of Techtron through, I have changed the fuel filter, Since it does not idle poorly or no performance problems, I just can not figure out what is going on. Any help?
You all have been great. Thanks in advance.
EARL

[JAB02LHS]

Re: Lean Fuel Mixture

Bad Sensor?

[Brad]

Re: Lean Fuel Mixture

Yup, first clean you MAF (Mass Air-flow sensor) and make sure your air filter is clean and seated properly. I know you can get the too rich error if the air cleaner isn't attached properly.

[Lindy]

Re: Lean Fuel Mixture

a couple of cents worth...of course the sensors are a bit differently situated between the '02 and '03-05 models. Do not touch the sensor, so as to avoid getting oily finger-prints upon it. There are aerosal spray-cleaing products for MAFs available at your local auto-parts store. Also, you may want to search for a thread on the topic.

[E'sBird]

Re: Lean Fuel Mixture

a couple of cents worth...of course the sensors are a bit differently situated between the '02 and '03-05 models. Do not touch the sensor, so as to avoid getting oily finger-prints upon it. There are aerosal spray-cleaing products for MAFs available at your local auto-parts store. Also, you may want to search for a thread on the topic.

Thanks Lindy: I searched several different scenarios that did not give much help. On the internet under code 174, listed EGR valve cleaning and new fuel filter. I had the new fuel filter so I went ahead and changed it. I am beginning to suspect that there may be a leak on the intake leading to the throttle body. When it warms up in Kansas a bit, say above freezing, I will return to the garage and check out all areas.
Again,thanks to all. If you have any other experiences or ideas, don't hesitate to contribute.
EARL