Replacing a 2003 TB EXT Catalytic Converter - HELP - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum



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Go Back   Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum > 2002 - 2009 TrailBlazer/Envoy Tech > 02-09 General Tech Q&A > General

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  #1  
Old 03-02-2010, 10:28 PM
CT_Trail CT_Trail is offline
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2003 Chevy TrailBlazer LT EXT
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Replacing a 2003 TB EXT Catalytic Converter - HELP

I started to replace the cat in my 03 TB EXT... Getting ready for a miserable job. Looked over and under the whole assembly and saw that the rear pipe to the muffler had only two studs with nuts. Soaked them in PB Blaster and hit the O2 sensor nut while down there. Let those sit and went to the top of the cat pipe on the end of the manifold. First of two bolts didn't seem to bad to get to, soaked in PB Blaster and let sit. Found a way to get to the last bolt up against the block, soaked that as well. Went back to rear of TB and removed the two under the car and the O2 sensor. Breeze....
Back up to the front two....
Remove the one closest to the block, sweet,,,... moved over to the one opposite,, spun right off with the impact as well.. Done....... Went to move the pipe and start getting it down and awww sh......t Won't move, closer inspection shows another bolt on top of the flange...

How the heck do you get to this one... It looks like a 16-20" 3/8 extension wedged between the tranny pan and the side of the cat housing. How do you get to this bolt at the 12 o'clock position???

Help.....

Thanks TB in CT
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  #2  
Old 04-01-2010, 03:05 PM
rhdune16 rhdune16 is offline
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Anyone can offer some help?

Did you figure this out at the end?
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  #3  
Old 04-22-2010, 09:48 AM
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longhorn262 longhorn262 is offline
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Yeah i was curious how easy it was to get off cause i was planning on gutting the cat out.
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Old 05-03-2010, 12:37 PM
CT_Trail CT_Trail is offline
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CAT removal

Well....
To start you have to support the transmission, remove the crossmember, and remove the rest of the exhaust all the way back. The tough part is the removal of the one bolt up against the engine block. There are 3 that hold the exhaust manifold upper flange to the CAT pipe. The first two are relatively easy to get to from the underside of the car. The last one is a PITA... You will need a 16" extension, a 6" extension, a universal joint and an impact wrench. That last bolt is a toughy... The best way to do it is be underneath the vehicle with someone on the top holding the socket onto the nut. You can only feel it from the top side.
Good luck and if you have any more questions just ask..
CT_Trail
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  #5  
Old 01-26-2011, 04:06 PM
ksucatz ksucatz is offline
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Loose....now what

Sorry to be bringing up an old thread, but wondered if you were able to finish removing the cat? I got all the fasteners loosened no problem, loosened the rear pipe from the hangers and slid back as far as it would go. Then I slid the cat pipe assembly from its hanger.....but could not go any farther.
Does the cross member need to be removed as CT_Trail said? Nothing else I saw said anything about this. Does the muffler pipe need to come completely out? How does that come out?

Thanks
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  #6  
Old 01-26-2011, 04:22 PM
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RayVoy RayVoy is offline
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Hate to toss in what may be a stupid question

But, if your removing the cat (to replace it), why not simply cut the pipe off and pull the old cat out of there.
With the cat out of the way, there should be access to the stud and nut.

Now, I know ya gotta put it back together, but it may be easier with new parts.

I can't imagine an exhaust shop pulling the cross member
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Old 01-31-2011, 07:14 AM
ksucatz ksucatz is offline
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Got it done Friday. Decided to just cut the old one out. The new one slipped right in. The new cat was a little thinner profile, so that helped.

On a side note....she runs like new!
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Old 01-31-2011, 10:32 PM
skoehlke skoehlke is offline
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Cat

Which one did you buy?
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  #9  
Old 08-22-2011, 07:05 PM
EXT 03 EXT EXT 03 EXT is online now
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Quote:
Originally Posted by skoehlke View Post
Which one did you buy?
+1 i think i will going this route soon
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