Hunting down my P0172
 

So I've been getting a rich code in my 2013 FRS, It's accompanied by a raspy start up that feels like it wants to stall but never actually does (it always evens out a few seconds after starting), a hesitation around 4000rpm that becomes more noticeable at WOT, and a pretty consistent misfire around 2.5-3000rpm.

I've cleaned the MAF, checked the intake and oxygen sensor, Replaced the spark plugs and had all 8 injectors cleaned and tested.

Mods include an intake, ft86factory header, nameless helmholtz resonator, and an invidia n1 catback exhaust

I've been chasing this issue on my own for over a month now so any input helps,

thanks in advance

Catted or uncatted?
If your not tuned I'd get that done first.

It's the catted UEL, and do you really think a tune would change that much ?

You are not tuned???

And the part you have is a nameless front pipe. The helmholtz resonator is just an add on to the part. This means you also have a high flow cat in the front pipe too.

Yes that's correct, If it was simply a tuning issue though that'd probably make my job alot easier which is why I initially bet against it being the problem.

Miss-posted a bit.
If you were uncatted it would matter, being catted I don't think it would matter as much, but I could be wrong.

Probably not, but it is not helping. I'd be curious what a log looks like. Could be coil pack but I would think it would be misfiring more.

Well like I said there is a pretty consistent misfire, usually around 2.5-3000rpm

Reading comprehension fail on my part :bonk: I would say likely a coil pack. Would be nice if you had a way to log so we could see which cylinder was misfiring, then rotate the packs and see if it follows to the other cylinder.

I'm ordering a set of coil packs tonight, I'll be sure to post an update on what happens.
I also heard someone say it could possibly be the camshaft position sensor but imma check this first and see what happens

small and easy fix first then move to next step
enjoy replacing coilpacks which i dont want to do with this boxer engine
i would replace spark plugs when you do this as well

Update: So I changed out the coilpacks, car feels noticeably faster at lower rpm but still has the hiccup and hesitation at 2000 and 4000 rpm

You mentioned you have an aftermarket intake. That would require MAF REscaling especially if it’s CAI

Update: So I found a stock intake, new MAF, new filter, still running rich. Problem is actually getting worse tho, as the car recently starting stalling out when coming to stop coming to stops and also occasionally while moving. Once again any help goes a long way,

After switching to stock intake, did you reset ECU?

You "checked" the oxygen sensor?

Make sure you do some logging, its hard to help without logs. See the software tuning forums on how to and different logging methods