In trying to fix the 3k hesitation, I followed what worked for s_vares: https://honda-tech.com/zerothread?id=1028177&page=8

Threw some seafoam in the egr ports and cleaned the egr valve. The hesitation is gone now but I got misfire code for cyl 4. Changed the plugs to a new set of copper ngk's and I'm now getting Misfire codes in 1-3. The second set of plugs look ok, so I'm a bit stumped. Full tune-up was done <15k miles ago including the fuel filter, so all the other goodies should fine.

Any ideas are welcome.

 

have you changed the cap and rotor? How much sea foam did you put into your motor

 

Cap and rotor were changed 15k miles ago. Half-can of seafoam through the egr port.

 

that's weird cuz when i had misfire code i cleaned mine with intake cleaner and went away.

Maybe you can try cleaning it again with regular air intake/carb cleaner. Get all the carbon inside the port.

 

Hello:
This message is for anyone with a Honda Prelude, I think probably gen 4 or 5 (I have an 'O1 SH). I went through hell with misfire codes and here's what it was: Your cyllendar exhaust valves need to be serviced (cleaned). I bought mine used at 64k miles, and had never owned one before. After about 4k miles, I was getting the misfire codes/ATTS light (the light automatically turns on/turns your ATTS off, if your check engine light turns on, since your ATTS uses engine power). Anyways, long story short, I was a virgin V-tech owner and I drove it for a while this way until finally my shop found the problem but it was too late. All my exhaust valves were shot and I had to get a complete valve job (~ $2800 since they replace everything that might get in the way). So basically, if you own a Prelude, get your valves service every 30K mi! It's only about an hour of shop time for a good shop to clean them and it saves you lots of hassle. I hope this helps your problem??

 

yeah, that's what mine to after i cleaned my egr I also adjusted my valve clearance and found out they were too tight. After that, CEL was gone.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gutlush &raquo;</TD></TR><TR><TD CLASS="quote">Hello:
This message is for anyone with a Honda Prelude, I think probably gen 4 or 5 (I have an 'O1 SH). I went through hell with misfire codes and here's what it was: Your cyllendar exhaust valves need to be serviced (cleaned). I bought mine used at 64k miles, and had never owned one before. After about 4k miles, I was getting the misfire codes/ATTS light (the light automatically turns on/turns your ATTS off, if your check engine light turns on, since your ATTS uses engine power). Anyways, long story short, I was a virgin V-tech owner and I drove it for a while this way until finally my shop found the problem but it was too late. All my exhaust valves were shot and I had to get a complete valve job (~ $2800 since they replace everything that might get in the way). So basically, if you own a Prelude, get your valves service every 30K mi! It's only about an hour of shop time for a good shop to clean them and it saves you lots of hassle. I hope this helps your problem?? </TD></TR></TABLE>

damn, $2800 for valves and a valve job? the labor must have been killer!!

 

Damn, for $2800 you could've just done a motor swap...You seriously got screwed on that deal I paid $1080 to have 10 valves replaced on my motor about a month ago. I could've done it myself, but I just wasn't in the mood to do it, but it at least reminded me of why I don't ever take my car to shops

 

Dude, check your valve adjustment then seafoam your motor thru vaccum line to remove carbon and hotspots.
should fix her all up for you!

 

Did valve adjustment yesterday. Car is running better than ever. Still got cel misfire cyl 1 though. Dunno what else to do now.

 

when you ran the seafoam did you pull out your o2 sensor. Seaform is known to kill o2 sensors. I think You might be able to take it out and clean it. sometimes it gets clogged with all the carbon and such the got released from the engine. after the use of seafoam.

 

The front sensor would be the one to get clogged right? I'm really short on time, so I'm just gonna order a new oem one at ~$40.

 

I can not garunntee that is why. I don't want you to waste 40 bucks and time. Its a place to start though.