Gean

I have an 03 LX civic standard trans and i put seafoam in it to try to boost mpg and after that it wouldn't idle at all when warmed up. I replaced the 02 sensor and iacv and now it will idle when warmed up but if there is a load on engine i.e. rad fans, power steering, windows, the rpm will drop like 200-400 then go back up or it will stall. After it stalls it cranks but doesnt start for like 5-10 mins but will bump start. there are no codes and i checked the battery voltage turned off and running and its normal so idk where to go from here.i havnt checked if the rpms drop that much when cold but im waiting for call to cool down right now.

Colin42

You probably screwed up the iac with the seafoam. Take it off and clean it/dry it

Gean

I replaced that and the o2 sensor already
also i believe there is a power loss while driving

Colin42

What brand are the replacement parts?

Gean

i believe the iac valve is bwd and the 02 sensor is bosch and i read after i bought it that bosch ones dont always work but i hasnt thrown a code and it runs the same with it plugged in and not plugged in

Gean

bwd 50545 and bosch 15710 to be specific

Colin42

Double fail. Need to use oe parts, denso for the o2 and I believe denso is also the oe for the iac. Grab one from a junkyard if you don't want to buy new. Or if you still have your old iac try cleaning it and reinstalling. You'll have to do an idle relearn as well

Gean

ill try that later and see how that works out. still thinks its dumb they can say its an oe fit but doesnt work properly

Gean

Okay i cleaned and put back the oem iacv and didnt change anything but i also found a thread that was having the same problem as me https://honda-tech.com/forums/honda-...ugged-3315901/
when the iacv is unplugged my car does the same thing so im going to try some of the stuff in that thread. also i would clean the old 02 sensor but the top of it is just missing so i think its junk.

Gean

got an oe 02 sensor put in and I cleaned and put back the original iacv valve and still nothing