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need help installing zzp 3" catted downpipe on 04 Impala SS

ryangtp89

New member
Hey I'm in the process of installing 3" catted downpipe on my 04 impala ss, right now I'm just soaking the bolts down for a few days with pb blaster. anyways the two bolts in the back look difficult to remove and to remove the stock downpipe looks hard. Is there any write up's or a printable instructions for this ? Thanks a lot! By the way I also bought a wizaired cai, tuned pcm, autolite 103 plugs and a 3.5 pulley, I had to drive it home with only the tune pcm, 3.5 pulley and cai, the mechanic was confused with the downpipe and didn't have time for the plog and spark plugs, was it a bad idea driving it home (20miles) ? I didn't make any boost I babied it home.
 


if they break off you can replace them easily. and let the car run for a little so everything gets hot and expands respray with blaster. let sit for 5 min and get to work. its easy
 
A swivel socket adapter may help you get those two top bolts as well, Harbor Freight has the impact ball joint style for very cheap.

Also try hitting on the flange a little bit with a hammer to help shock it loose. It helps the PB Blaster penetrate deeper.
 
Sounds good, I have been hitting all of the bolts for the past 4 days with pb blaster, I let the car sit in my driveway soo that way it wouldn't burn off, gave me a good excuse to take the wrangler to work.
 
Sounds good, I have been hitting all of the bolts for the past 4 days with pb blaster, I let the car sit in my driveway soo that way it wouldn't burn off, gave me a good excuse to take the wrangler to work.

Yea honestly you wont be reusing the bolt so just try to take them out and if they break or if you cant get them out cut them, then just head to the hardware store or parts store and pick up some grade 8 course thread bolts to replace them.
 


The guy at the shop didn't do it again he was afraid he was going to break the bolts on the head and the downpipe. Well time to find another shop.
 
would it be safe to drive around for alittle without the downpipe and plog ? the tuned pcm, 3.5 pulley, Al 104 plugs and wizaired cai is already on.
 
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103s are a little cold for a stock compression car running 10 psi. 104 would be more appropriate. Less misfires at idle and better fuel economy.

As far as the pulley without exhaust mods, just don't get into boost and all will be okay.

Better idea would be to scan and see if you have knock as is. You might not, but likely will.
 
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I'm sorry I do have the autolite 104's I had to check my sale order on my email to make sure. But defently stay away from the boost is what I have been doing.
 


what does n/m stand for ? Is there any write ups for removing the front exhaust manifold ? It looks tight, just wondering if theres any tricks to remove it.
 
what does n/m stand for ? Is there any write ups for removing the front exhaust manifold ? It looks tight, just wondering if theres any tricks to remove it.

Pb blaster for a couple days. Let the motor run to heat it up and steady pressure don't wrench on it.
Edit: there is a recent thread on it
 
Thanks a lot guys! I went through 2 cans of pb blaster and let it sit for a week before I brought it to the shop but they were still too much of a nancy to try and remove the exhaust manifold. Well I went ahead and bought some Kroil! If you guys never heard of it look it up!
 


just installed it and its still loud, i left out the o2 sensor because the old one was stripped finally installed new one and its sounds the same. the downpipe never came with a gasket. should i get one ?
 
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