'97 Exhaust Header (will a '95 header fit?)

[jacob]

I've gone through 3 stock exhaust manifolds in ~4 years. I'm sick of these horrible castings. They crack in half where the four ports become one and then the truck sounds like garbage and slogs around everywhere. I would love to just pay the couple hundred to get a nice header. I don't even care about the performance gain (if any), I just want a header that will last. The problem is, I can find headers for up to '95 KA24Es all day long but they all say they won't fit a 96 and up. Is this an emissions thing or a fitment thing? I don't have to do smog testing, so if the '95 header will fit my '97 manual 4wd, I'll slap that puppy on and drive into the sunset happy! Anyone have experience with this?

P.S. I've checked my timing a hundred times to make sure it's not a timing issue making the exhaust run abnormally hot. I think it's just bad castings causing the exhaust manifold to crack.

[EF2]

see if you can cross reference a schematic for an oem 95 exhaust setup vs the 97 but put in the same trim etc that yours is as the 95 and see what’s different. otherwise someone with more knowledge on these setups will respond soon. hope you can get one that’ll work, i’m sure that’s so annoying having to replace that so often.

[Deerhurst]

It's likely an emissions thing. If you need an extra bung somewhere an exhaust shop should be able to make a hole and weld one in. Same for moving a bung.



I have 90-95 3.0 V6 headers on my 86.5 with a 3.3L V6. The difference for me was the emissions bungs. Also my Y pipe wasn't wide enough but not something you have to worry about with the KA.

[LugNut1990]

Three times? It's an engine issue -- running too rich, most likely. Emission controls still in place and fully functional, e.g., your upstream O2 sensor? Even a really bad air filter can cuase such.

[jacob]

Originally Posted by LugNut1990

Three times? It's an engine issue -- running too rich, most likely. Emission controls still in place and fully functional, e.g., your upstream O2 sensor? Even a really bad air filter can cuase such.

No check engine light or codes, doesn't smell rich, inspect and clean my air filter often. If it is running rich, it's only slightly rich. IMHO, it's still a bad casting if it cant withstand a slightly rich burn. Pretty sure I can get the approximate air:fuel ratio off my OBDII scan tool...I'll check that out when I can. Most components were replace ~57k ago when I rebuilt the motor and tranny, and the components that weren't were thoroughly inspected and/or cleaned. Now that I write that...I do think it's time for new plugs (57k really goes quick).

[Deerhurst]

Originally Posted by LugNut1990

Three times? It's an engine issue -- running too rich, most likely. Emission controls still in place and fully functional, e.g., your upstream O2 sensor? Even a really bad air filter can cuase such.

Lean is hot, rich is cold.

[LugNut1990]

Definitely not in the cat, as the excess fuel gets burned there. And I'm suspecting that maybe his problem is in one cylinder (if not overall) so that there is excess oxygen and thus combustion continuing in the exhaust ahead of his cat. Even a bad, or using no exhaust manifold gasket, or bad torquing/cracking the manifold, could be contributing.

[Stinky]

Is your exhaust glowing...this could indicate a plugged cat.

[LugNut1990]

That would do it too. Or other major restriction in the exhaust system that is unrecognized by the driver (who keeps pushing it despite the lack of power).

[jacob]

Originally Posted by LugNut1990

...that is unrecognized by the driver (who keeps pushing it despite the lack of power).

Not sure where you got this idea, but thanks for the internet diagnosis.

Turns out this 3rd manifold wasn't cracked yet, and it had already gone through the cheap ring gaskets at the base of the manifold which caused the noise like the previous cracked manifolds.

The answer to my original question: yes, the early year header will fit (with some fabricating) on a '97 KA24E 4WD extended cab manual transmission hardbody. I purchased a header for the '90-'95 4wd KA24E hardbody. I had to ever-so-slightly tweak the header flange angle at the head (probably only a degree or less) to get the bottom to sufficiently clear the front drive shaft. This was honestly the hardest part, as I had to build a jig to hold the header while I gently bent the upper tubes slightly to change the angle of the flange that forms the gasket surface at the head. I also had to move the O2 sensor port to a totally different location to clear the bulkhead. This involved cleanly cutting it off the number 3 tube, and forming a patch to weld in the vacant hole at its original location. I then drilled and welded it a bit higher on the number 2 tube. I also built a bracket for the O2 sensor connectors which bolts to the inner left fender. I had to slightly tweak the EGR port to line up the threads with the EGR tube, but it was otherwise already at the correct position. The supplied lower tubing and gasket bolted right up to my cat, and I chose to weld this lower tube section together rather than clamp it with the supplied u-clamp. I also went and purchased a generic rubber hanger and fabricated my own hanger which I welded to the frame. The old hanger from the t-case didn't line up as good as I wanted it to.

Anyway, trucks running like a top now and I think this new setup can easily last well into the future. 257k and counting