Bucking after gutted cat.
 

Log attached. But I recently gutted my cat, same day (after I gutted I reset the ECU and did a brake stomp) i took it out for a hard run. Did amazing. (except for the small tune imbalance) anyways did amazing ran well got it up to 130, cooled it back down parked it, let it sit some more with the hood open and turned it off. Well after gutting the cat I snipped the rear o2 sensor wire off, useless basically. Told my AP to delete the CEL (just in case). Noticed my AFR gauge doesn't work anymore (i'm assuming because of the snipped o2 sensor?) but still ran great in the mentioned run.

Few hours go by and me and the wife go to the gas station, and its bucking real hard. Running super lean. But only at under 3k RPM. Anything over that i get into boost territory and everything gets fine...

LINKING TO THIS THREAD AS IT SEEMS TO HAVE GENERALLY THE SAME ISSUES IT SEEMS: https://www.rx8club.com/series-i-tro...h-idle-247180/

You should have just unplugged the sensor wire, not snipped it . Anyway , which gauge are you talking about that stopped working ?
I presume an aftermarket gauge on your dash - why on earth would that be hooked into the stock rear sensor ?????

Yes an aftermarket guage on my dashpod. just flashes 7.4 now as if its not getting signal. I would have just un bolted and bolted it back in but it was stuck so i figured, wth. Doesn't do anything now anyways.

Just for clarity so we know what is going on ....

Can you confirm :

You have a stock front o2 sensor in the Greddy down pipe ?

an aftermarket gauge sensor also in the Greddy downpipe ?

The stock rear o2 sensor in the gutted cat - with the wires snipped ?

I assume

I assume, there's only one wire plugged into the downpipe.

Yes

There is one of those square plugs inputs above the rear o2 sensor spot with nothing plugged into it.

From what you just said it seems .....
The rear o2 sensor was already eliminated and what you snipped was the wire to the aftermarket gauge . The stock front sensor is the one in the downpipe from the sounds of it . But can you confirm that the wire from that front sensor goes to a plug at the rear of the engine ?

Yea the front sensor goes to the engine and at this point i'm pretty sure the rear went to the gauge cause the regular plug is hangin there zip tied up. Fuck. . . i think i see where this is goin....

buuuuut, if its that i just clipped the gauge wire...why would it only affect me at ~<3k

Well snipping that wire should not have affected anything except your gauge .But wanted to clarify it all seeing as your problem is related to fuel delivery.

In that case I can't really see why what you did could cause the issue . The fact that it goes lean at low loads but then comes right makes me wonder if something is up with one of the P1 injectors.

Probably need to see logs at higher rpms/loads to see if all is normal in that load range.

Alright. How ya want the log done?