Im currently in the middle of a top end motor rebuild and im trying to eliminate as many options as ican. somethings that im removing with this rebuild are the stock air cleaner assembly, i found an adapter the lets you use a regular air filter on the stock carb and not have the stock bulky eye soar. also connected to the air cleaner are 3 tubes that run all the way around the front of the block and run down to the exhaust. conveinintly taking the system apart there was a metal plate that has perfectly alligned holes to cap off the exhaust and a gasket that was already used for the tubes to connect. my blower motor or the whole setup doesn't work at all my vents just blow air right on through but none of the air control switches work, now my truck is equipped with A/C but im opt'ing to remove this just for a cleaner look and that i cant use it. well thosei willdefinitly be taking off or changing. but i was cleanin some parts and organizing things today when i thought of the first catylitic converter located right below the exhaust manifold, and i was wondering if these clog and can cause running issues, and if it was possible to just run a straight pipe in its place instead. aren't there like 3 converters in the system would it hurt to remove one. or better yet, this is out of the picture right now, but is anyone have custom headers/ whole exhaust system?

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this is my header and the converter connected, that would be one short pipe, is that thing making that big of a difference?

 

hey which motor do you have? i have a 91 b2600i and thought i only had one cat.

 

i have an 86 b2000, 2.0L motor. i was just looking in the haynes repair manual and i saw the picture in chapter 4 on page 4-11 of the later model exhuast and the part i guess im reffering to is the center catalytic converter, that also has the air injection pipe that connect to the exhaust which i'll plug. Even on the next page 4-12, it shows the later model exhaust with a straight pipe in its place and only one converter, i havent looked under my truck in a while but im leaning toward replacing this pipe. i'll look underneath tomorrow

shibby.

 

Oh one other thing, i didnt think i needed a new post for this, but i brokea nipple off of my water thermo valve, the fitting that screws on right under the manifold, it has two nipples coming off it, and vacuum lines running off it, i was just wondering if anyone knew where to get this, would napa carry something like this or what.
thanks

 

Yes cats can become clogged, and in all honesty should be changed out overe 60,000 miles or so on these old engines. When they clog they not only cause ALOT of back pressure but have been known to cause blown head gaskets as well... This truck also only has one cat, the other thing down the line is a resonator and then a muffler... Good luck.

 

hey, im very interested in just removing the cat and putting in a straight pipe same location, mounts, blah blah blah, i dont have to pass any emissions here, whats up with the resonator, just like a silencer before the muff or what, these motors dont rely on the cat at all for added back pressure do they? mine looks clogged for sure. you said it can cause blown head gaskets, well add a horrible cooling system to the mix, i just sent my head in for a rebuild and found out it was cracked between #2 and #3 valves, so im gettin a new one now, but im sure my cat helped ruin everything. i just ordered my new parts should be rebuilding soon! finally

 

dump all that crap, cats, etc.............install a header from pacesetter,and with that 32/36, you'll sound right! if you want more power, throw a 38 dgev weber, but your gas mpg will go down. might also throw in a diff cam if you install that weber 38. goodluck
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thanks, thats tempting to get a header. i was just looking at pacesetters and i only foundheadersfor 83-84 b2000 and 2200, so i dont know how that would work cuz i got an '86, i cant afford it yet but, i'll look into it. first i need to get rebuilding, and save for that carb...