Dennis P writes:

Subject: Car Codes - You helped us!

I just wanted to say that my wifes '98 Lincoln Continental was stalling while driving slowly and/or stopping at lights, etc... and we took it to the Advanced auto store and they put the tester on it and said it was the Coil and spark plug needed replacement. We changed that and it did not get better. We thought they gave us a bad one, so they exchanged it and we installed the 2nd new one and still the auto was stalling. We took it in again and yesterday they said it was the fuel filter. We took the car to the Ford garage and had that changed this morning. Still not working right. They did a diagnostic test and came up with the PO171 and PO174 codes. I ran that through the internet and found your site and read your comments about this. When my wife read that there might be a leak in a hose, she told me that she had heard hissing noises over a week ago and told me about it then. I didn't pay attention to that and forgot about it until she said, "I told you I heard those types of sounds a while ago"! So I checked the hoses and found that there is a leak at an elbow in one of the hoses! So we just had the filter changed for nothing and wasted $60. bucks, but with your suggestions, we were able to repair the problem ourselves and not have to have the expensive repairs done which according to you would have been a waste of money also! Thanks for your help and I will recommend your site to all I know! Thanks again.

Dennis Bandy writes:

Subject: Common Misconception

It's a common misconception that a scan tool or code reader will tell you exactly what to replace. It also helps to have an understanding of how systems work and what is most likely to cause specific problems.

The fuel filter you had replaced may not have fixed the running problem you were having, but they should be replaced as normal maintenance anyway.

Thanks for the comment, I'm glad that my article helped and please rate the article if you haven't already.