Which Catalytic Converter is Bad on My Ford F-150

2004 Ford F-150 Lariat 4×4 exhaust pipe exiting resonator on driver side warm. exhaust pipe on passenger side exiting resonator hot which catalytic converter is bad? and can you clean out the carbon?

How much of a heat difference is there?

There is a significant amount of difference. drove truck for about 30 min. and was able to hold hand on exhaust pipe driver side. it all started when i replaced all 8 broken spark plugs that ford installed.

Usually the hotter side would be bad, as it’s either more clogged, or getting a richer mixture dumped down it. Was is misfiring prior to your repair? That would have been dumping excess fuel down the exhaust which will really heat up a catalytic converter.

It was showing code p0174 and skipping under a load going uphill sorry it took so long to respond helped with grocery.

Yeah, that would do it. If enough fuel went through the converter, it can cause damage and ruin it’s functionality. If it is staying excessively hot, you’ll have to replace it.

I think i miss understood, the one that i can hold hand on after 30 min of driving is the good one.

Yes, the hotter side converter would be the bad side.

I was told that the out going side would be hotter than the engine side the info came from (MR. MUFFLER). can you clean them out.

The side that is hotter, which if it’s bad it should be REALLY hot, is the faulty side. The catalytic converter is burning the unused gasoline from the misfiring (skipping) and gets excessively hot. No, you cannot clean them out.

I replaced the spark plugs back in aug. truck is running fine (WELL WITH NO CHECK ENGINE LIGHT) I REPLACED FORD PLUGS WITH CHAMPION double platinum. Received that info from federal mogul website cars direct site listed the champion plugs as top rated for emmissions but will not last as long i have 225,000 miles and still love my truck.

Ok, well either way if you have one bank of cylinders running hotter than the other through the exhaust, most likely the converter has been fouled with too much fuel or poor mixture. If it gets bad enough, it should set a check engine light with a catalytic converter performance code.

I agree with you Protech. That’s what’s throwing me off. There is no check engine light but I am feeling heat. The converter is under my feet and I can feel high heat through the floor board and it feels like I have to mash the gas a little harder.

That is typical telltale sign of a bad converter! I would recommend replacement soon, so there is no other problems caused by it.

Do you recommend a certain brand?

Yes, factory parts ONLY!

DIrect Fit or Universal?

Catalytic converters from a muffler shop are junk and will fail you quickly.

When you say factory parts, do you mean go to Ford or do you mean direct fit from Magniflow or Walker, etc?

I mean go to Ford. You will pay more, but it is ALWAYS worth it.

Thanks. One more question: kept having gritty debris in the cab thought it was back pressure from exhaust. but found steel idler pulley rubbing on aluminum timing chain cover. have you ever heard of this and what health risk can i expect? have been sick.

It would be extremely hard for debris from the engine compartment to make it in the cab unless you have a problem with the ventilation system. As for what it can do to your health, I have no idea. Have never heard of that before.

Yeah ford had 2 body styles in 2004 new body style does not have cabin filter and could that destroy my converter thanks and have a good night.

Thank you, have a good night.

1994 Ford Ranger

 I just replaced the engine in. Now it won’t stay running. I disconnected the MAP and it was better but still would not run below 3000 RPM. Any ideas?

Sounds like you’ve either left something disconnected, or you have a massive vacuum leak somewhere. Is the check engine light on?