Mustang Club of Maryland

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Jim DeAngelis

The car is a 1998 Mustang gt 4.6 sohc. I first had P0171 and P0172, I have a C&L 80mm MAF which made it run a tad lean. I cleaned everything (MAF) and put new plugs in and the problem went away. Shortly thereafter, I got a P0402 (excess EGR flow) code and the car ran horrible. I then inspected the EGR system for leaks and replaced the EGR and all valves / solenoids related. The car ran great for about ten days and then I started getting the P0401 code (insufficient EGR flow). The P0401 code did not affect the car at all and I lived with it. Now, the car has a temper of it's own...I'll get the P0402 code randomly and the P0401 always. Could my 02 sensors be bad and not recording the correct temperature?

Cliff

Problem solved!!! Advanced Auto used to sell GP Sorensen parts....suspiciously they stop carrying the brand. Want to know why? Because they were making / selling defective parts!!! I discovered that GP Sorensen was manufacturing / purchasing EGR valves with the wrong diaphram!!! I took the EGR that I bought back 3 times over a year and each time they assured me it was the correct one even after I mentioned that they were different (size) from the factory part.

So on a whim, I purchased a Ford original and sure enough the car runs like a champ again...I will never go back to Advanced Auto...

I did get my money back of course.

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