h22 idle problem

[18itr]

Ever since i got my headers and exhaust done the idle drops down to 400rpm then slowly climbs back up.
Only happens after the car is driven warm, turned off and then driven again. The car is running a hondata s300.

Any ideas?
- o2 sensor?
- tune?

[sultanaz]

mine does the same thing and im running it stock, im really curious as to why it happens. shits me off so much.

[94vtirozguy]

i would have got a retune after you got headers... you could be running too rich which has in turn fouled up the EGR valve and / or your o2 sensor. Or they could have damaged the 02 sensor when they installed the headers.

[3rdGenPrelude]

i just got my head replaced on mine and the exhaust manifold aswell.. same problem lol. iono what it is, my friend with his 4th gen got the same problem too. he said it's his o2 sensor cause he fked about with some things then just super glued it back on lol =\.. haha.. so yeah maybe they damaged it. sounds like a fair explanation

[sultanaz]

i dont know if this is problem your h22 has but the problem with mine is EXACTLY what ur saying and about a week ago i but i cleaned out my throttle body with the throttle body cleaner stuff ( they tend to get really gunky after a while ) .. after i started it up and all the black shit came out and ever since the idle has been PERFECT and the car actually drives ALOT better too.! ive been trying to fix it for ages now ive been driving for a week since i did it and wow its never driven so good and it isnt droping revs !!! all it takes is a lil pin hole to be blockd up and it can throw out ur revs !! so yeah

hope this helps mate !!!!!

[zillacles]

What do you mean? My 94-96 H22 has an EGR valve, although I've blocked it off.

[kccord]

Please check the tab as shown below on your s300. Increase your idle speed from the point of above 100*F. Also increase the IAC duty a bit. If your idle isn't hunting, it rules out FITV blockage. Since your car is running with no problems (beside this), fouled O2 sensor is on the bottom of the scale that may cause this problem.