Few questions, had the coolant system checked out in my car, and the mechanic told me that the exhaust manifold had a small crack in it, which may explain why it is running lean....

I was wondering, the exhaust manifold and the headers are the same aren't they?? If not, how hard is it to change the exhaust manifold, and is there a smog legal aftermarket on eto buy? Thanks guys

smog legal no

headers are easy to install you can get some on ebay or get pacesetters if your ona budget

other wise their are bosal and greddy and couple other good headers out there...

Bill

2 Questions for you. Now I am not trying to be a smart ass, I am by no means a GURU when it comes to this stuff. I want to know for my own knowledge.

1) How would an exhaust leak (cracked manifold) cause you to run lean?

2) How would an after market header make it not smog legal? Now I don't live in a state that has smog laws, but if you keep the stock Cat, wouldn't that be enough to keep it in specs?

Thanks in advance!

>2) How would an after market header make it not smog legal?
>Now I don't live in a state that has smog laws, but if you
>keep the stock Cat, wouldn't that be enough to keep it in
>specs?


i'm with him.... wouldn't the difference between header and manifold is the change in the flow and (slightly) direction of exhaust gasses? the o2 sensor is still there, just the flow has changed

>1) How would an exhaust leak (cracked manifold) cause you to
>run lean?


i'm wondering on this one too. i mean wouldn't a leak in the manifold cause the o2 sensor(s) to pick up a signal where not as much gas is being combusted cause of the leak and your ecu will give it more gas making you run rich? feel free to correct me if i'm wrong.

If you live in certian states, Cali being one i think, you have to have the aftermarket prodect (regardless of what it is) either CARB approved stamped on it or the receipt (or equivilant) show it is CARB legal.

well yeah, and then after making you run rich it would see extra uncombusted fuel and run leaner

i think the problem was more that it was fluctuating from rich to lean and back and forth as he explained it

I would just find someone with a TiG welder, drive around to get the manifold nice and hot, and weld the crack with a high Ni rod.
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i'll sell you my stock exhaust manifold if u want it. its heavy as whoa. $15 + shipping? let me know.

if you can find the crack u could use some jb weld on it, that should most definatly hold it together...

unless u plan on goin' turbo i'd say save some $$ and buy headers...

good luck, later

WTB: Dodge Omni


http://www.geocities.com/shadyporshe851proof/frame_content/indexframe.html

mods: star stage III clutch + 60mm tb + the normal mods, bass, lights well u get the picture

JB Weld will not hold up to that kind of temperature, let alone the expansion rate of the cast iron. To have a crack seal, and stay sealed, it must be sealed with something with the same thermal rate of expansion. In other words, metal of similar composition. That is why I recommended a weld with a high Nickle content rod, and to have it welded while red hot. That way, the filler is the same temperature as the manifold, so that they can both cool at the same rate without pulling away from each other. Or maybe I am full of bullshit. Go ahead and try bubble gum.
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JB weld works on cooler items like engine blocks and intake manifolds. I bet you'll have a tough time getting it to permanently seal on the exhaust manifold (its rather hot). I once tried to use JB weld to hold a stud for my downpipe. It turned to white dust in a few weeks.

Corbin

'95 ESI-T
HRC+FMIC+ETC...



Gimme fuel...Gimme fire...Gimme that which I desire

Hehe... Corbin said "white dust"... hehe...
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