I am going to replace the catalytic converter on this 96 Jimmy because it rattles and I'm getting repeating p0302 codes. This Jimmy is new to me and I have just experienced the adventure of replacing the starter. Is replacing the catalytic converter equally frustrating and difficult? Do I have to remove any other parts to replace it? Any fancy tools? All tips highly appreciated.

 

p0302 is a cylinder misfire, no?

p0420 is the code for the cat (can be o2 sensor issue rather than cat, anyway)

Make sure that's the source of your rattling before you get all gung-ho about it; it could just be an exhaust rattle against the frame that has nothing to do with the cat.

You probably need a cutoff wheel, chisel/prybar, BFH. You may have to screw with exhaust plumbing if your new converter isn't the same length.

 

Bang on the converter and you can tell if the converter is rattling from the honeycomb coming loose inside the converter. The only thing that can be hard is if the bolts at the front & rear of the converter pipe are rusted. use a good penetrating oil and a GOOD 6-point socket. The nuts can decrease in size due to rust. Pick the tightest fit socket metric or american to reduce the risk of rounding the nuts off. Extreme cases will call for heating with a torch. The oxygen sensor can also be difficult to remove. I have had to use a torch and when it came out it stripped the threads. No big deal other than needing a new oxygen sensor because the new converter pipe will have a place ofe the sensor. It is a bit of an art to get the old converter out once it is unbolted but it will come out.
Just replaced one on a 99 Jimmy that was making lots of noise. The converter was also plugged up as the power really improved with the new converter. Also don't throw the old one away. The converter recycle places will pay you for the old one.

 

i have a 98 chevy blazer 4 door with 4 x 4 and i had a question on replacing the O2 sensors when you replace the cat. Do i have to replace the o2 sensor when replacing it with the direct fit cat? and what did you mean when you said "No big deal other than needing a new oxygen sensor because the new converter pipe will have a place ofe the sensor." ? please elaborate and let me know if i should replace the post cat o2 sensor at the same time as i replace the cat

 

Unless you are getting codes for the O2 sensors, I wouldn't replace them. A clogged cat can foul an O2 sensor though, but I still would wait to see how it runs with the new cat before replacing them. If you do have to replace them, go with AC Delco only.

 

I agree about not replacing the downstream 02 sensor unless you get a code for it after yoy replace the cat. What I meant by no big deal is since I was replacing the cat there were new threads to put the 02 sensor in. If I was re-using the old threads I had ruined them getting the 02 sensor out.
If the 02 sensor does not want to come out try heating it with a torch and if you don't have a torch run the engine to get it good and hot. Then spray a good penetrant such as PB Blaster on the threads while it is hot. It will smoke but the heat can draw the penetrant into the threads. This might allow you to get the old sensor out without damaging the threads.

 

thanks for the great advise guys! i appreciate it, im ordering the new cat today, direct replacement by magnaflow

when looking under my car i noticed two brackets welded onto the pipes coming off the cat. these brackets are obviously attached to the car. But i can take them off (I think). Are these easy to attach from the point of attachment at the car? But the main problem is that i cant find a cat that has both mounting brackets already welded on to it. I would want this to insure easy installation. Any one know of a product with the two brackets already welded on? does it really matter to have any brackets in general? Would one bracket do just fine? and how do i know if the brackets on the new one will be in the right place where the old ones are now? and i am going with the direct fit cat just to point out.

 

Hey! As I JUST did this job on my 97 here is a list of the parts and tools you will require:
New cat,new gaskets for both front and rear flanges,new hardware to install the new cat ( I used stainless ) Now for tools:an oxy/acetylene torch first and foremost! You will never break free the front flange hardware and you will also find that the front studs are exactly that;pressed in just like wheel studs! The hangers are stubborn to come off but they will,lube them well a few days before,that'll help. I simply unplugged my down-stream O2 sensor then removed the driveshaft and that gave me enough room to rotate the whole assembly so I could slide it out,but use caution not to damage the sensor if you plan on re-using it(the sensor is MUCH easier to remove on the bench IMO,but is also easy to re-install under the unit once the new converter is in place!)Strait-forward job 3 hours easy!

 

i dont have this equipment and i would like to do it in the cheapest but easiest way possible. as i said i dont have a oxy acetylene torch, nor do i know how to use one. I was wondering if anyone knew where to get the cat with both hangers already welded on. If not, i found a direct fit cat with one hanger already welded on. So would one hanger be enough to hold it up?

because my hangers are welded on to the pipe thats already on my car now

the cat on my car now has the hangers welded on to it.

and maybe I'm crazy, but do the magnaflow direct fit (part # 23455) actually have 2 hangers already welded on?

I might be missing it but i only see one. i might be wrong so let me know

 

http://www.rockauto.com/catalog/x,ca...,parttype,5808

Got the Walker Direct fit for my 97 about 40,000 miles ago.
So far so good. Photos show you pretty much what you get.

Mark K