Rep Power: 0

so i have a 2008 honda civic Si sedan and has 188k kms right now. so it started this winter 4 months ago. i was at work i was going for lunch and so i remote started my car and then suddenly it started to have a fluctuating idle and then when i drive it upon low rpms or acceleration, it like hesitates and jerks everytime. everytime i start and drive the car now it drives like ****. it is also worse upon cold start. and sometimes when its been driven for maybe hours it will go away and drive like normal.and then as soon as i shut the car off and start it again then it does the same thing again, idle fluctuating. also i am not sure if this relates to this but i have been reading forums about AC systems going bad on 8th gen civics. so everytime my radiator fan goes on then my ac compressor clutch would go on as well. then as soon as the rad fan shuts off and so does the ac compressor. it always happens that both of them comes on and off everytime. someone help me please i couldnt chase what the heck is wrong with this car. im at my limit and is about to give up!!

 
Rep Power: 224

Do you have any faults? Check engine light on?

A dirty idle air control valve (IACV) can cause idle issues.

 
Rep Power: 0

i only have an o2 sensor code for the sensor 1 buy i've had that code way way before this happened maybe a year before rhe fluctuating idle happened. and i do mot have an IACV because k20z3 is electronic throttle body control (ETCS). mine is noy equipped with an iacv. i recently replaced my intake manifold gaskets assuming that i had vacuum leak and after replacing it, nothing happened. engine still surges and hesitates.

 
Rep Power: 210

Read: https://www.k20a.org/threads/how-to-...ng-etc.220377/

 
Rep Power: 0

thanks for all your help guys i finally found tye culprit!!! SO AFTER DOING LOTS OF EXPERIMENTS I FINALLY WAS ABLE TO BORROW MY BUDDY'S CIVIC SI. A GOOD SOURCE CAR. I TRIED SWAPPING MY MAP SENSOR TO HIS AND WAS STILL LIKE THAT.I HAD A HUNCH THAT IT COULD BE THAT WAS BECAUSE I TRIED PULLING OUT THE CONNECTOR FROM THE SENSOR AND THEN MY IDLE STABILIZES. SECOND I TRIED SWAPPING MAF SENSOR AND THAT DIDNT FIX IT. I TRIED SWAPPING ETCS RELAYS TO MINE AND HIS AND A COUPLE RELAYS LIKE PGMFI AND STILL DID NOT FIX IT. AND SO I WAS LOOSING MY MIND NOW.AND THEN I CONNECTED OUR SHOP SCAN TOOL AND WATCHED FOR LIVE STREAM OF MY SENSORS ETC. I FOUND THAT MY AIR/FUEL DATA IS FLUCTUATING AND SO THAT MADE ME THINK. WHAT IF I SWAP MY A/F OXYGEN SENSOR FROM MINE TO HIS. AND ****ING FINALLY AFTER ****ING MONTHS AND MONTHS OF CHASING THE PROBLEM. I CLEARED MY CODES AND SWAPPED OXYGEN SENSORS AND THEN STARTED MY CAR AND THEN BOOM! IT FREAKIN FIXED MY ISSUE.NO MORE FLUCTUATING IDLE.I'VE BEEN ASKING PEOPLE IF IT WAS MY OXYGEN SENSOR THAT IS DOING IT AND THEY KEPT SAYING NO AND SO I BELIEVED THEM AND STILL TRIED TO IGNORE MY CHECK ENGINE LIGHT THAT I HAD FOR A YEAR. SO PEOPLE "DO NOT IGNORE YOUR OXYGEN SENSOR" CODES. SPECIALLY THE SENSOR 1 OR THE A/F RATIO SENSOR. FIX IT BEFORE THIS HAPPENS TO YOU. I GOT CARRIED AWAY OF OTHER THINGS THAT MIGHT BE THE PROBLEM BUT IT WAS JUST MY CHECK ENGINE LIGHT TELLING ME.HAHA MY AIR FUEL MIXTURE WAS MESSED UP AND THAT IS BAD PEOPLE!

 
Rep Power: 0

thanks for all your help guys i finally found tye culprit!!! SO AFTER DOING LOTS OF EXPERIMENTS I FINALLY WAS ABLE TO BORROW MY BUDDY'S CIVIC SI. A GOOD SOURCE CAR. I TRIED SWAPPING MY MAP SENSOR TO HIS AND WAS STILL LIKE THAT.I HAD A HUNCH THAT IT COULD BE THAT WAS BECAUSE I TRIED PULLING OUT THE CONNECTOR FROM THE SENSOR AND THEN MY IDLE STABILIZES. SECOND I TRIED SWAPPING MAF SENSOR AND THAT DIDNT FIX IT. I TRIED SWAPPING ETCS RELAYS TO MINE AND HIS AND A COUPLE RELAYS LIKE PGMFI AND STILL DID NOT FIX IT. AND SO I WAS LOOSING MY MIND NOW.AND THEN I CONNECTED OUR SHOP SCAN TOOL AND WATCHED FOR LIVE STREAM OF MY SENSORS ETC. I FOUND THAT MY AIR/FUEL DATA IS FLUCTUATING AND SO THAT MADE ME THINK. WHAT IF I SWAP MY A/F OXYGEN SENSOR FROM MINE TO HIS. AND ****ING FINALLY AFTER ****ING MONTHS AND MONTHS OF CHASING THE PROBLEM. I CLEARED MY CODES AND SWAPPED OXYGEN SENSORS AND THEN STARTED MY CAR AND THEN BOOM! IT FREAKIN FIXED MY ISSUE.NO MORE FLUCTUATING IDLE.I'VE BEEN ASKING PEOPLE IF IT WAS MY OXYGEN SENSOR THAT IS DOING IT AND THEY KEPT SAYING NO AND SO I BELIEVED THEM AND STILL TRIED TO IGNORE MY CHECK ENGINE LIGHT THAT I HAD FOR A YEAR. SO PEOPLE "DO NOT IGNORE YOUR OXYGEN SENSOR" CODES. SPECIALLY THE SENSOR 1 OR THE A/F RATIO SENSOR. FIX IT BEFORE THIS HAPPENS TO YOU. I GOT CARRIED AWAY OF OTHER THINGS THAT MIGHT BE THE PROBLEM BUT IT WAS JUST MY CHECK ENGINE LIGHT TELLING ME.HAHA MY AIR FUEL MIXTURE WAS MESSED UP AND THAT IS BAD PEOPLE!

 
Rep Power: 210

I typically look at an o2 or a/f sensor as a 100k mile replacement item as part of routine maintenance. Anymore, even factory oem sesnors are generally affordable.