ARH Header Install

I installed ARH headers with Toyota gaskets and dirtydeeds exhaust around 2 two weeks ago. After a few days I noticed that it wasn't maintaining a constant idle and was revving up and down about ~50-75rpm. Very noticeable. Was also looking at the short term fuel trims and noticed the bank 1 pretty erratic. So I started listening in the wheel well and could hear an exhaust leak. Then I noticed that the header wasn't 100% aligned with the head curvatures and the nut stud not centered in the bolt hole of the header. The pic is the number 7 cylinder. (closest to the firewall).

So last weekend I removed the left side mid pipe, unbolted the front drive shaft and unbolted the header completely in an attempt to correct the alignment. So this time, I tried maneuvering it to align better with the head, but it just wouldn't move. Once I get it onto the 8 head studs and 2 AIP studs, it just seems to be locked in place. I was pressed for time so I just let it go back into the same position and tightened everything back up thinking maybe I just needed to get it tighter.

Still having the same problem. Yesterday, I duct taped the outlet side of a shop vac to my tailpipe and sprayed soaping water around the header. I actually did see a few bubbles between the 1 and 3 cylinder. Tightened it up along with every other nut and don't see any more bubbles. Started it up and thought it was good until I drive it. Still having the same problem. I swapped the AFR sensors from each side and still have the same results. I can't really hear a leak like I could the first time though.

Do ya'll think this misalignment could be the problem? Only way I can think to fix it is to take all the studs out first, but not sure how I would even get them back in tight once the header is in place.

I am so frustrated right now and so tired of wrenching on the same thing and getting the same results I don't know what else to do but to take it to a shop and hope someone more experienced than I can fix it.

 

You call ARH?

 

No, I haven't.

 

This.

Nick will talk to you himself and he will pin point what's up. Call him and see what he says.

 

I was gonna say, when installing headers on my Tacoma it was required to remove two of the header studs in order to even do the install.

 

Are any of the other holes in the header offset, or is it just that one?

 

Here's more pics of the other bolt holes. Really hard to get good pics at night so not sure they will help any.

 

I'm probably SOL on that one since I didn't buy directly from him, but I don't know for certain. So worth a try I guess.

That may be what needs to be done in my case. I think I've read every thread on header installs and nobody has mentioned it. Maybe i missed it.

 

I didn't buy from him either. He provides support for the products he makes. I've had to replace the H pipe and he did it no questions asked.

 

Here is what I am seeing on my obd app for my tundra. When I look at my wife's '18 4 runner, the fuel trims are very similar regarding B1 and B2.

 

Sounds like there’s a leak at the collector.

 

The collectors were leaking after the initial install. They are sealed now though after I applied some red rtv.

 

And it still surges

 

If the bolt holes are bigger than the stud just make some centering dowels for the two outside studs.

if you’re using stock gaskets it’s likely leaking at the header flange. The stock gaskets seal really well on stock manifolds. Headers need a more compliant gasket.

if the rpm is surging you have a leak and the o2 sensor is seeing this air and the ecu compensates worth more fuel. This causes idle time drop. So the ecu raises idle snd over compensates.

 

Did you ever get this resolved? Did you use new stock gaskets? About to do this same setup and was curious! I wonder if this was error in the header build or what happened.

 

Do you have a recommendation for what gaskets to buy with the ARH? (Which gaskets does ARH send with the headers usually?)

 

Yes, it has been resolved. I didn't have the time anymore to pull the headers and reinstall so I kept thinking of other things that may be causing the idle surge. I ended up doing a relearn all values via techstream and that seemed to fix it. Hasn't had any surge since. Not really sure what the deal was. I used OEM gaskets from toyota.

 

Glad you got it squared away. I didnt run into any of that with my install. Now enjoy that added power

https://www.tundras.com/threads/just-another-arh-lt-review-pic-heavy.72677/