Power loss - Catalytic Converter problem?

[M1lrtym]

I have a 2000 SOHC 4.0 that has lost power over the past week to the point of being undrivable. I also noticed a rattling a figured it was the catalytic converter causing the problem but when getting under that car I can't tell which is the cataltic converter. The rattling is coming from (starting from the muffler) the second "metal box". Is this the converter or is this a resonator or something? It looks like it has two converters, one one the driver side exhaust and one on the passenger side that both lead in to this one box that is rattling. There is no engine light being thrown. I felt the pipe before and after this box and there is a significant temerature difference (barely warm vs. can't touch) after just running a minute. The throttle response is slow, engine runs fine at idle but just no power at all. Any help would be greatly appreciated. Thanks.

 

[Turdle]

There are 4 cats on these trucks-an exhaust shop should be able to check them.

Have you tried cleaning the maf sensor-or other basic tune up items?

 

[M1lrtym]

I just replaced the spark plugs and I have a K&N air filter that I just cleaned but no, I haven't cleaned the MAF sensor. This was such a major power loss that I figured it would have to be more than just a sensor. This weekend I couldn't even go up a slight incline on the highway faster than 40 mph.

I was just going to order a magna flow direct fit converter but when going to their website to find the right part it recommends a passenger and driver side cat (two different parts) for the type "E" engines (SOHC) and the type "X" engines it shows a dual inline cat. It's almost like I would need both if I were going to replace all of them. I guess I'll take it to a local shop and get them to figure out which one is bad.

 

[Turdle]

Bingo!!

K&N oil on the Maf sensor--

reasearch this.

 

[M1lrtym]

I probably shouldn't have said "just cleaned". It's actually been a few months since it was cleaned. Either way I will clean the sensor since it relatively easy to do but I doubt this will help my current situation. Thanks for the info.

 

[COBRA]

If the pipe feels hotter after the cat then it's fine, if the pipe is hot before the cat and cool after the cat-it's plugged. If the problem is in the second set of cats you can take the pipe off and break it up with a bar and a hammer. You'll get more power and should still pass smog if the primary cats are still working. At least you'll be able to drive again even if you have to replace them at smog-test time. As for the mass air meter, if you just serviced the K&N and used too much oil or didn't let it dry thoroughly it will get oil on the MAF and should be cleaned. You can buy a spray stuff at the auto parts store that's made specifically for them-don't use carb. or brake cleaners or any other strong solvents. Rubbing alcohol works well but you'd have to apply it with a Q-tip or something like that and the sensor is very sensitive. The spray lets you get the job done without having to touch the sensor wires and guarantees you won't accidentally damage it.