On our 2003 Honda Accord 4cyl the motor has been dropping idle and throwing the check engine light for Low idle and catalytic converter. I just put a new motor in the car due to low compression on #3. We never had the problem with the old motor. What happens is when you start the car it will idle at 750-800 and once you put it in gear it drops to 600 range. Once you turn the AC on it will drop to 500 rpms and the CEL will throw. But when the car is in park it idles perfect!

I know on my other two cars (older hondas) we have an idle screw but I can't find one on the k24. Does anyone know the best way to adjust the idle? I plan to replace the cat on the car or just hollow it out since we don't have emissions here in KY. Any ideas?

 

Anyone?

 

The whole AC problem is a giant PITA. There is more than one screw on the TB that you can adjust with the IACV, theres a high likelihood that its getting stuck or gummed up. Make sure your AC fan is coming on and everything with that, or its not low on refrigerant.

Can you tell me what codes your throwing so I can look them up?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by msedacca &raquo;</TD></TR><TR><TD CLASS="quote">The whole AC problem is a giant PITA. There is more than one screw on the TB that you can adjust with the IACV, theres a high likelihood that its getting stuck or gummed up. Make sure your AC fan is coming on and everything with that, or its not low on refrigerant.

Can you tell me what codes your throwing so I can look them up? </TD></TR></TABLE>

I already know what codes they are, I have a pocket scanner and a booklet. But one is P0420 and I believe P0526 (i can't remeber right off the top of my head).

As far as refigerant it very well could be low, could it cause the issue with the idle?

 

TTT

 

420 code is from the misfire from the previous engine. Did you bleed the coolant? The IAC valve has coolant going through it. Just make sure there is no air in the system, reset the ecm and do the idle relearn. ( hold the throttle at 3k until the fans come on then let it idle for 10 min) You will have to replace the cat to fix the 420 code though...bummer.

Good luck

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vapor40 &raquo;</TD></TR><TR><TD CLASS="quote">420 code is from the misfire from the previous engine. Did you bleed the coolant? The IAC valve has coolant going through it. Just make sure there is no air in the system, reset the ecm and do the idle relearn. ( hold the throttle at 3k until the fans come on then let it idle for 10 min) You will have to replace the cat to fix the 420 code though...bummer.

Good luck</TD></TR></TABLE>

This is 100% incorrect. P0420 is a catalytic converter code. Misfire codes are P0300-P0304 on I4 and P0306 on V6s. The P0300 is a random misfire code while the others are cylinder specific.

If the cat is restricted it could potentially cause an idle problem and will certainly cause driveability problems.

P0526 is not a real code.

 

Maybe I was not specific enough. The cat was damaged by the misfire.... this happens all the time. The 420 does not mean it is restricted. It is not doing it's job any longer.

Any luck btw?

 

ttt again

 

The codes were:

P506 and P420

The other day we were driving and the CEL went off and has yet to come on. Its been off for almost a week. Car has never ran bad even with the CEL on. The idle would only drop if the AC was on. If we leave the air off the CEL would never come on before. Still with teh AC on the car will read at 600rpms which is still kinda low. But I'll leave it for now!