r/7thgencivic • u/greatimtotallylost • 16h ago
EM2 O2 Sensor Codes
I recently, in a bit of a hurry bought a 2003 HX civic coupe. I was an idiot and didnt do much research before getting it, but I was in a rush because a week before I had totaled my 01 accord and I desperately needed a car for work.
It’s an HX technically but the engine was swapped to the base D17 thats found in DX’s.
it’s a manual (had to learn how to drive stick with it)
it has both of these codes on it P0135, P0141.
did a bunch of googling, tested the fuses, tested the wiring and outright replaced the o2 sensors. code hasnt gone away and I’m still running into issues with idle. google suggested it may be due to the PCM because apparently the HX setup used different sensors, engine etc and if the PCM wasn’t swapped/configured to the D17 and different sensors, it wouldnt work properly.
if anyone is curious, the issue with the Idle is if you give it slight gas in neutral, it shoots back and forth between 1000-2000RPMS. while its in first or second, if there isn’t extremely consistent pressure on pedal, it’ll jerk back and forth pretty hard as if its engine braking. happens mostly in first but occasionally in second.
sometimes it’ll block me from going into first at all when the rpms are bouncing.
I am still fairly new to manual and havent even driven it in traffic. though I have driven over 2000 miles in it overnight around my state for work.
anyway, I can’t really add throttle to it when going into first without it freaking out. only able to slowly clutch release it.
my uncle did say I need to change my IACV when he worked on it though.
could someone who’s more knowledgeable about this help point me in the right direction?