Hey everyone,

Well I was trying to remove my O2 sensor and it ripped off the pipe! haha what luck.

Anyway, I'm going to weld the O2 sensor bung back on the pipe, so I disconnected the 'federal pipe' from the exhaust manifold.

So, the front of the 'y' pipe is loose, and I removed the pipe clamp between the catalytic converter and the 'y' pipe.

Now, I cannot get the pipe disconnected from the converter! I sprayed down with PB blaster, and tried a little more. I even took two tie down straps and tried to basically seperate them that way, but that really didn't work out too well.

Am I missing something? They don't look welded, so perhaps just rusted badly? Should I heat the outer part with a torch and try to seperate them?

Jim

 

Heat it up, then rapidly cool it. Repeat as necessary until it comes free. Pipe clamps pinch the material together and can cause things to never want to come apart.

 

Heat it up cherry red and take a small screw driver and pry up under the lip to loosen things up that might help.

 

thanks! I'll give it a shot and let ya know

 

Ok, here it goes.

I got it off with an air chisel. My little propane torch didn't cut it.

I gutted the cat, and got the new O2 sensor on the Y pipe and reinstalled everything.

I broke two bolts on the exhaust manifold, so I struggled with new bolts and exhaust leaks for a day or so.. that was a real challenge.

Then I somehow reattached the 'Y' pipe onto the converter (well, the empty converter), and it leaked a bit, but I wrapped it with a repair kit and 3 clamps and its pretty good to go.

I took it for a test drive and I immediately noticed a substantial difference! No more surging or bogging down at ALL.

So, I then drove the truck up to Canada for vacation and back.. 1300 miles. It ran like a champ and according to my calculations, I got around 21 mpg.

I'm having an issue with the overdrive not wanting to disengage unless I push the pedal to the floor. I think the TCC is ok though (if I press the brake, it disengages, etc)

Jim

 

doesnt your 95 blazer have an O2 senser before and after the catalic converter in order to moniter the exahust going in verse the exhaust going out after the converter? wont it through and engine code with the cat hollowed out? also how did you hollow it out? my 95 S10 cat rattles inside, why?

 

Actually, no. I didn't see one and I didn't get a code or anything. From what I read it should have one, but I can't find the sensor or the wiring for it after the cat.

Well, I had the 'Y' pipe off, and I could see inside the catalytic converter. I took a steel chisel about 2' long and hit it with a hammer and smashed up the insides, then put my shop vac on the pipe to vacuum it out.. It takes quite a while but it got the job done. Pre-96 vehicles are not emission inspected in this state, either.

If your cat rattles inside, its probably bad. Did you hear it rattle if you hit it with a rubber mallet? If so, you could probably do the same thing that I did. If you have an O2 sensor after the cat, you could probably get away with an O2 simulator.

 

i have a 95 S 10 pick up with a "W" vin vortec engine and i have 2 O2 sensors one before the cat and one after the cat. so can i hollow mine out to? or will i throw a code. i think yours didnt throw a code because you only have 1 O2 sensor before the cat right? whats an O2 simulator? my cat rattles when the car is idling... but im sure if i hit it with a rubber mallet it will rattle. but i didnt hit it yet cause i hear it rattling at idle...so what are my options? thanks

 

It depends on which one of the three PCM configurations the truck has. If it is the OBD1/2 or OBD2, then yes, but a few early 95's came with a true OBD1 configuration which would only have 1 O2 sensor directly ahead of the cat.

As far as hollowing out the catalytic converter... People, PLEASE replace the cat. A properly functioning catalytic converter does not hinder your power any where near like many people think. You can actually have a more restrictive exhaust with a hollowed out catalytic converter than with a properly functioning one. The reason is that the cat expands out in size. This is to allow for increased flow across the catalyst, but when nothing is there, it acts to cool the exhaust flow, contracting it, slowing it down, and thereby adding restriction.

 

under my hood on the emission sticker where it shows the spark plug gap, it also say in small writing, " OBD 1 Certified" so i gues my truck is OBD 1 ....
also i want to hollow the Cat beacause i cant afford the crazy price of a new one. and also, anytime the engine runs bad, the Cat gets ruined....and these blazers and S10's are notorious for running bad....so that doesnt help the situation either....