My friend has a 2000 Honda Prelude SH. Its throwing codes for misfires in cylinders 1,2,3, and 4 and also a random misfire... The CEL goes on and off as it pleases and right now we are stumped. Also, this car burns alot of oil, but we heard that it is typical of this engine... Its more or less 2 qts. for every 3000 miles. Anyone, with any idea of whats going on here, please post. Thanks in advance guys.

 

Bump, we need help.

 

What do the plugs look like? What have you guys tried so far to fix it? I'd start with a good tune up...

 

We did a tune up 7000 miles ago which included plugs, wires, dizzy cap, rotor, and fuel filter. The plugs are bronzed over and look fine. We did a pressure test and everything was fine. We put in a B&G fuel additive which cleans injectors, (its proven, I own an automotive shop and it works wonders, better than Sea Foam.) Is it possible that the ECU could be fried?

 

You could try another ECU and see if that changes anything...

 

What brand spark plugs and wires? When's the last time the valve lash was adjusted?

 

I was receiving misfire codes with a flashing CEL on my 2000 SH, it turned out to be the EGR valve.

 

Been through this nightmare..

Clean your EGR valve and get the EGR plugs out on the intake manifold and clean the runners. It will take an afternoon, and you need to remove a bunch of stuff.

It is most likely EGR if the light is coming on at low load, low RPM, high gear kind of driving.

 

they do burn oil , dont worry about it. its how the engine is designed. all four misfires could be a vtec pressure problem. if the oil is more thant 1.5 quarts low vtec will not work properly, and or clogged the screen in the spool vavle, engauging the vtec at the incorrect time, causing codes or misfires.

 

We may try to clean the EGR since you had the same problem. Thanks a lot.

 

i would def look into the egr valve. also make sure ur running ngk plugs and oem wires, cap and rotor.

 

It is running the OEM NGK's, but it has NAPA wires, cap, and rotor. Those parts are the last of my concern considering we primarily use NAPA products on every vehicle that passes through our shop. The wires are by Belden and are of very good quality. All NAPA products meet or exceed OEM standards. I think the EGR is the best bet and I will post when we try to fix it.

 

im not saying the aftermarket ignition stuff is junk but it my experience as a honda tech i would only use oem ignition parts. but like i said ur egr valve and the ports that are probably clogged are most likely ur problem.