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Discussion Starter #1
I apologize if this has been covered before but I haven’t seen anyone with the same problem.

I have a mini me turbo setup. D16y5 block with y8 head. Stock internals with ARP headstuds boosting 12psi. Car is also dyno tuned and has a p28 with hondata s300. So the car has been fine for the past few months after the tune until recently I started hearing a ticking/exhaust leak sound and it runs lean under WOT. It usually sits at 11-12 afr under boost but now climbs from 12-14 quickly and I let off immediately. I checked valve lash and it they were all still set to 0.8 and 0.10. I have new gasket from turbo manifold to downpipe. Running open dp. Timing is on point. I asked my tuner he suggested I check the adj. cam gear to see if it slipped but it didn’t. Spark plugs are brand new bkr7e 0.28 gap and injectors are Acura RDX 410cc. No misfires or anything weird other than the exhaust leak sound. Any ideas? dizzy isn’t leaking oil and looks good. Coil wires are also brand new. Wanted to see what you guys think before I go ahead and replace injectors and what not. Oh and I also have a walbro 255 fuel pump. I appreciate any input. Thanks guys
 

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93 Civic HB SI
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Its your exhaust leak more than likely. If it still sounds like its leaking, you need to fix it.

Wideband oxygen sensors sense "oxygen", a leaking exhaust upstream from the wideband sensor will draw fresh air into the exhaust stream, and skew your AFR readings.

If the car was fine till the exhaust started leaking, and still feels fine, then the tune is probably still fine, and the exhaust leak is drawing in pre-sensor oxygen giving you a false lean indication.

Find the leak, and fix.
 

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Discussion Starter #3
Thanks for the input. That’s what I was thinking and been trying to find the leak but no luck. But even when I had a blown turbo gasket my AFR held solid so that’s why I wasn’t too sure it would be an exhaust leak but I may go and get the turbo manifold resurfaced to make sure that’s not the issue
 

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If you bring it to a reputable shop, you can tell them to smoke test the exhaust for leaks.

EVAP leak testing machines pump out a thick white smoke under a small amount of shop air pressure, and they can pump it into the exhaust tail pipe opening while on a lift, and watch for where the pipe or fittings might be leaking from.

What kind of manifold do you run? Is it a cheap ebay ram horn stainless manifold? Those things are known to crack at the collector flanges all the time. Welding them back up doesn't work, and will crack again in a few weeks.
 

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Discussion Starter #5
I have a go autoworks log style manifold I suspected a crack too and took it off to check but couldn’t visually see any cracks or damage but I’ll probably look for a shop that can smoke test it
 
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