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Plugged Cat?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by grtwhite, Apr 9, 2002.

  1. grtwhite

    grtwhite 1/2 ton status

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    Anyone know what symptoms would be present if a catalytic converter was plugged? Just changed out an Idle Air Control Sensor & a O2 sensor. Previously it was running really rich & idleing speradicly. Since I've replaced the sensors its not running rich anymore & still idles a little odd. Not sure if I need to adjust the timing or the cat is plugged. The truck is running better but seems to hesitate or be slightly uderpowered, when excellerating occassionsally she'l run great with plenty of power. Just thought I'd ask you guys for some advice on trouble shooting. Thanks!!
     
  2. Hossbaby50

    Hossbaby50 3/4 ton status

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    When the cat went out on my Dads F350 it was on its way out when we bought it and didn't know it. It ran good (we thought) but then one day started to loose power, and then go to the point where it wouldn't even run. Once the cat was replaced it was like night and day. It had twice the power of when we bought it. It would spin the tires off the line, and ran like a raped ape. It never idled weird until the cat was almost all the way shot. Hope this helps a little bit. Try disconnecting the exhaust system at the exhaust manifolds. If it runs and idles good with the exhaust unbolted then your cat is shot. That is what I would try.
     
  3. dyeager535

    dyeager535 1 ton status Premium Member

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    Typically I would say that a plugged cat converter results in consistent problems, not an intermittent problem. (heat buildup, loss of power, just what Hoss was talking about)

    Have you done the basicas like cap/rotor inspection, and wire/plug replacement if necessary?
     
  4. Zeus33rd

    Zeus33rd Smarter than you GMOTM Winner

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    Hmmm, I don't know about you guys, but when my cat gets plugged up, I just feed it some ex-lax. It unplugs itself in a hurry. /forums/images/icons/smile.gif lol!

    I couldn't resist that one. /forums/images/icons/smile.gif
     
  5. 86K5inMN

    86K5inMN Registered Member

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    I just had the cat replaced on my 86 305 Blazer last week. It slowly started to go. At first there was a slight hesitation which eventually got so bad it took at least a block to accelerate to 30mph. The carb needed a rebuild at the same time as well. The carb was probably lean a little causing it make more heat on the exhaust side and eventually melted and plugged the cat. It ran decent when it was cold and after sitting for a weekend would run great for about 5 miles and would then go to hell. I would say if there is a doubt it should be replaced.
     
  6. weisel

    weisel 1/2 ton status

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    I had an s-10 blazer and decided to replace the cat one day (had it brand new sitting around) and it was completly different. Sooooo much more power. I would say if there is a doubt, replace it cuz it can't hurt anyways.
     
  7. txbluethunder

    txbluethunder 1/2 ton status

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    you can do like i did. took it to a muffler shop and had them pressure test teh cat...they drill a hole before and after and test the difference in pressure between the two. it only cost 20 bucks also.
     

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