I have a 98' Expy with the 5.4 motor. I love it to death, but recently have had a weird sort of problem. I have duals on it, but when climbing long hills I get that rotten cat converter smell. I don't know why, but am considering hollowing them out.....Any input on the subject? I'm lost and wondering what to do about it

 

The smell is a symptom of rich mixture and not the fault of the cat. converter.

 

Is the 1970 Clean Air act still around?

Regulatory Overview

The 1970 Clean Air Act prompted the development of catalytic converters, which reduce harmful vehicle emissions by as much as 90 percent. Catalytic converters cause a chemical reaction in the exhaust gases while they are within the emissions system, changing harmful emissions into relatively benign emissions. Tampering with emission control devices (such as catalytic converters, exhaust gas recirculation valves, air pumps, etc.) is illegal. This anti tampering law applies to individuals as well as to businesses. Individuals may be fined as much as $2,500 for each vehicle tampered with, and business are subject to fines of up to $25,000. Note that businesses that sell used vehicles must ensure that the vehicle is equipped with all emissions control devices that were originally installed by the manufacturer. To ensure that shops are in compliance with the anti tampering law, you must follow specific procedures when working with catalytic converters, including ensuring that proper replacement parts are used and that all required paper work is completed and kept on file.

 

Thanks for your feedback, but what can I do to get it to stop smelling so bad. Why is it running so rich?

 

Cylinder mis-fires can cause gas to pass on thru to the cat's but I am told the computer can figure this out and turn the injector off for the cylinder that is mis-firing.

This is probably normal going up long hills.

Read this...

"ROTTEN EGG SMELL FROM CATALYTIC CONVERTER"

http://www.sjmautotechnik.com/TROUBL...G/exhaust.html

How is your gas mileage?

 

Thanks for your help, I'm gonna replace the O2 sensors and see if that helps out.

 

how many cats does a 97 f150 4.6l have?

 

they have 4 cats,2 elbows and 2 big ones.check your plugs,coil packs and boots.they'll make it misfire too.you can buy replacement boots for about 5 bucks and they are usually the problem.they wear out and let water get in down to the plug and make it misfire.and you can actually be fined $10,000 for tampering with emissions control devices and $50,000 if you're a dealer or shop who sells a car without them or takes them off.but i'm just hard headed and did it anyway