2002 XLT Catalytic Converter Noise

[Squilax]

I have been hearing this metallic scraping, rattling noise coming from under the front of my truck. It happens when I start it up, when I accelerate from a standing start, when turning corners, and when accelerating going uphill.

When I had it in the shop a couple of weeks ago, I asked them to check it.

They told me that the noise was coming from the catalytic converter - other than the noise, it did not affect mechanical operation of the engine and really does not need replacing.

Even though there is nothing wrong, the noise is extremely annoying.

Can I fix this without having to replace the converter or is this something I just have to live with until the converter finally breaks down?

Thanks.

Steve

 

[L4CX]

Well, It is an emission Device, so if you live in a place were there are strict rules on Emissions you might need to get it fixed as soon as possible. My truck had that rattle noise for a while before I got it fixed. I'm not aware of a way to fix it without replacing it. It is really anoying though. I'm sure if there is a way, some one will chime in. There are alot of smart people on this board. They know their stuff.

 

[EasyRhino]

If it is a heat shield it does not affect anything, and is an easy fix. There are plenty of heat shields under our Ex's that can make these noises.

If the noise is coming from the cat itself, then you have a problem. If the cat body is making the noise, there is something wrong, as these are fairly sturdy.

If the noise is coming not from the case, but inside the cat, you do have a real probelm such as the matrix material is loose (not a good thing), or the internal structural pieces are loose (ditto also not good).

The shop's answer as stated is non-sensical.

 

[Squilax]

Thanks for the replies.

I haven't noticed and H2S smell coming from the converter - can it go bad without giving off that odor?

 

[muzzymaniac]

Reach under and see if one of the shields is loose. I usually yank them off if loose.

 

[Squilax]

Now the "Service Engine Soon" light is on...

Saturday, I noticed the "Service Engine Soon" idiot light came on.

I checked to make sure my gas cap was attached firmly, and checked the owners manual also. It says that this light comes on when there is a problem with emissions equipment. Is there a way I can check to see if the catalytic converter has gone bad?

I'll look online to see how I can get a new one and plan to install it myself if it needs to be replaced, but I need to know if that is the cause of the problem light coming on.

Thanks for feedback!

Steve

 

[muzzymaniac]

Go to Autozone and have the codes read. WRITE down the code and post/search it here. Don't leave without getting the exact codes.

 

[Squilax]

Thanks muzzy!

 

[Squilax]

Troubleshooting codes

P0141 - A malfunction exists in the heater circuit for oxygen sensor 2 in Bank 1

P0171 - The fuel system for Bank 1 was too lean

The guy at Autozone gave me a printout schematic of the Cat Converter and location of all oxygen sensors for Bank 1 and 2

"Oxygen sensor defective" came up on both of these codes.

I'm going to check the circuit fuse, then check the sensor connection.

If these both check out, does this mean I may need to replace the sensor?

I searched these codes in this forum and the search came back with no matches.

Thanks muzzy.

Steve

 

[muzzymaniac]

Ok, judging from what you've written, I'll assume the CEL is a new addition to the problem. First off - how many miles do you have on it and what motor? It's good to put this info in your signature so you don't forget to add it. Anyway, O2 codes are a pain cause they can be caused by many things. The most common are exhaust leaks, vacuum leaks and burnt/broken wires. I'm really cautious about advice on this since I'm not an expert. If it were me I'd look to see if the wires are broken - maybe caused by the mechanic looking around. Then replace the 02 sensor- it'll be the one after the cat on the pass side. I've seen post where people have swapped the rear 02's to see if the codes jump to the other side. Have you tracked down the rattle yet?

A little o2 reading...

http://www.explorerforum.com/forums/showthread.php?t=149917

 

[Squilax]

you're reight - CEL is new wrinkle

4.0L engine - 113,350 miles. I put this in my sig line.

Will check the wires and if intact, will check the fuse. If fuse is intact, I'll replace the sensor. You said to replace the one after the CAT - that would be Bank 1 Sensor 3 according to my diagram. Bank 1 Sensor 2 (the one that is malfunctioning) is the one located between the CAT and the exhaust manifolds on the "Y" pipe.

I clicked on your link and read the post on O2 sensors - thanks for the link. I really did explain a lot. It mentioned that these usually get replaced around 75,000 miles, so I guess for them to last past 110,000, they're doing pretty well.

Once the sensor gets replaced, will the Service Engine Soon light go out on its own or is there a reset switch somewhere to turn the light off?

No, I still cannot find the rattle. I think I'll have one of my sons start the engine for me so I can locate the noise myself under the hood.

 

[Potomac30]

My '93 had a similar rattle. Wrapped some stainless steel hose clamps around the heat shield and snugged it up... rattle gone.

 

[muzzymaniac]

4.0L engine - 113,350 miles. I put this in my sig line.

Will check the wires and if intact, will check the fuse. If fuse is intact, I'll replace the sensor. You said to replace the one after the CAT - that would be Bank 1 Sensor 3 according to my diagram. Bank 1 Sensor 2 (the one that is malfunctioning) is the one located between the CAT and the exhaust manifolds on the "Y" pipe.

I clicked on your link and read the post on O2 sensors - thanks for the link. I really did explain a lot. It mentioned that these usually get replaced around 75,000 miles, so I guess for them to last past 110,000, they're doing pretty well.

Once the sensor gets replaced, will the Service Engine Soon light go out on its own or is there a reset switch somewhere to turn the light off?

No, I still cannot find the rattle. I think I'll have one of my sons start the engine for me so I can locate the noise myself under the hood.

I read that mileage stuff a lot but I've never had a sensor go bad. Use a broom handle or a thick glove to press on stuff to see if the rattle stops. What worries me is that you have a rattle AND a code. As for location I thought there was 4 on these beasts 1 on each side before and 1 each side after the cat. I'm still very new to Ex's and haven't spent much time under it sa you may be right.

 

[Squilax]

I couldn't see the cat from above when I looked under the hood - where exactly is this beast located? Underneath?

 

[Squilax]

I couldn't see the cat from above when I looked under the hood - where exactly is this beast located? Underneath?

OK - found the cat underneath. Now to check the circuit - I looked up in my owners manual for the power disitribution box but don't know which of the fuses are for the O2 sensors circuit to see if the fuse is blown.

Does anybody know which fuse I should be checking?

 

[muzzymaniac]

Sorry, no idea.

 

[dmac0923]

just check all the fuses, sometimes electrical parts are on the same circuit of something else you would never think it would be grouped with. the time spent searching for the particular fuse

 

[missy]

I'm wondering about the rattling sound too. When I speed up or hit bumps I hear what sounds similar to chains rattlilng under the front of my Ranger. I also have alot of black exhaust, strong smell and am going through gas like crazy. Anyone have any ideas? I'm new to the site, so any help would be a huge help.

 

[EasyRhino]

I'm wondering about the rattling sound too. When I speed up or hit bumps I hear what sounds similar to chains rattlilng under the front of my Ranger. I also have alot of black exhaust, strong smell and am going through gas like crazy. Anyone have any ideas? I'm new to the site, so any help would be a huge help.

Missy, this is an old thread and you may lose many folks when they see the old dates, meaning that they never get to your question.

I recommend that you start a new thread.

Lots of good helpful folks here, some one with some good clues will come by. Be patient, sometimes the traffic here can be on the slower side.

And welcome to the site.