Catalytic converter replacement on a 4.0L 1997 Aerostar.

[DarylJ]

After replacing the defective flex pipe on my Aerostar 4.0L, a strange rap/thud noise could still be heard when accelerating. When up to cruise speed, the sound disappears. Couldn't find it by standing next to the van, so next was to head to the repair shop and put it up onto the lift. When up on the lift, we were able to isolate the source of the noise by running the engine, putting into drive, applying the brakes, and lightly pressing the accelerator pedal. Viola, the noise reappears, and it's coming from the converters. No holes in them, but they sound very hollow and "tinny" when tapped. Checked the voltage at the O2 sensors, before and after. Both readings are the same, indicating that the converters aren't affecting the exhaust gases passing through them at all. There are two converters. Couple of questions: Can one converter be used as a replacement for the two, or if not, can two universal cats, such as Magnaflow, be used as a substitute for the OEM units to cut the cost of going to the local Ford dealership for new replacements? Or, are there other cost effective substitutes that can be used? Specific model numbers appreciated. Thanks for the help!

 

[BrooklynBay]

Check the exhaust diagram on Walker or AP's website. Each manufacturer makes their own parts so the fit might be different for certain things. The OEM Ford exhaust is usually different than what these manufacturers make.