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I have a 2000 Honda Prelude Manual with 120k. My wife used it as a daily driver for a year until some maintenance issues occurred . This is my recall of what happened. On a Thursday night I put some fuel injector cleaning in car. She drove 60 miles on Friday. We went away for the weekend. Monday came and on her way to work about 15 miles she gave me a call saying engine light is blinking. I took the car down to a family members mechanic shop. I did a diagnostic on the car and error codes are pictured below. I already knew there was a combustion buildup in manifold too. I replaced the ck sensor, timing belt (water pump was done within year time), spark plugs, wires, and all belts. Once that PITA job was done I still had EGR and misfire. Did a compression test and cylinder 2 was dead. Did a valve adjustment and soaked the cylinder with combustion cleaner over night. Compression came back but EGR and misfire was still present. I swapped the EGR and EGR solenoid from my parts car. Took car for drive and got a puff of smoke for quick mintue. I noticed as I drove the engine light was on but not blinking. When I stopped the light started to blink. Few weeks later I pulled the injector and had them cleaned. Still have the issue. Pulled the EGR and it was not clogged.

Is there anyway to figure out what is clogged or what is causing the 2 codes (P1399 and P0401)?

I have a spare intake and head but I do not want to take engine apart again.

Other work done.... axle, replace all upper hoses, clutch, rear pistons, battery, tire and factory wheels.

Prelude H22 is a PITA.

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HELP!!!!!!!!

Sparksman

try cleaning your MAP sensor, may be the misfire.

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I am going to try that tomorrow. Is there anything else I should check?

Sparksman

The MAP adjusts the timing on OBD2's, did you replace the dizzy cap and rotor as well?

That build up in the manifold you talking about, is that what you think is causing the EGR to not have proper flow? If so no choice other then to remove and clean if you dont want to throw codes.

You could always go OBD1 which is better in the long run if local laws will allow.

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No I did not replace dizzy cap and rotor. I did test the spark with spark wire and plug off dizzy cap. I am getting spark.

I have another head and intake from parts car. What is the average price to have intake cleaned? Not looking forward to removing head.

As far as OBDI conversion, i am not going to mod the car and want to keep car stock.

Sparksman

Na I do my own work so I dont know most shop prices. Its not very hard to remove the intake, maybe hour taking off, and a hour to put back on. The intake is only a half dozen bolts and can be cleaned with brake spray cleaner. Try to clean both the intake and head.

I would replace the cap and rotor inside. Those are cheap parts and well as the PCV valve, and inline fuel filter. Those shouldnt be over looked when doing a regular tune up.

Are those Denso plugs your old or new plugs?

What brand wires did you buy?

Both cheap plugs and wires can result in a misfire.

NGK wires are the best next to actual Honda wires, and NGK Iridium plugs are the best for you're engine.

holmesnmanny

When you say pulled the egr, does that actually mean you pulled the egr plugs and somehow they weren't plugged ? Just because the 2 inch wide egr valve duct doesn't appear to be plugged doesn't mean the 1/8 inch wide egr ports aren't clogged.

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Denso Plugs are new not even 19 miles on them. Same for wires. Once I get it running I will change to NGK. I do not think that could be the problem.

I am going to look into changing the intake.

I really want to pin point the issue than just swap in new parts. I do not want to spend another $500 in maintenance parts and not resolve the issue or know whats causing the issue.

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I removed and inspected it. Then cleaned and reinstalled it.

Sparksman

Denso makes good quality parts, Honda uses them to make many OEM parts.

What heat range are you're plugs? If you live in Arizona you want a cooler range plug, same as a hotter one in say the Artic Circle. I know those two are extreams but even Honda recommends in generally warmer climates to run cooler plugs. I live in WA, most of the year is cool and mild, I run the NGK iridium plugs which are hot burning plugs. N/a engines benefit from a hotter plug, VS forced induction ie turbos, superchargers, or combo of both. Even N20 "NOS" needs cooler plugs.


Well look, there are only two possibilities why your EGR isnt working. 1- the EGR itself is bad electronically, or clogged. 2- The manifold/head ports are clogged. There are sensor sensitive sprays to clean electronic bits as well. If you use the wrong cleaner spray it can ruin a good sensor.

Remove intake, clean all the ports. Then try to clean all you can see on the head side. Put it back on with new gasket, reinstall EGR after another cleaning. Unplug your battery for 1 minute to reset the computer. Then start the car and see if its still throwing a check engine code.

If it is then Im pretty sure you're EGR is bad, and you need to buy a new replacement. Maybe all together after new gasket maybe $20 bucks invested and 2-3 hours for a novice.

I dont know where you got $500 from, maybe at a shop. You can tear these cars apart with damn near a basic walmart cheap starter tool kit. Just need the will power to want to learn and you can save a ridiculous amount of money. The PCV valve, fuel filter, rotor and cap should be less then $20-$25 bucks and helps your car run better more reliably.

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$500 was for crank position sensor, spark plugs, wires, and all the belts.

I have lots of tools. I will give it a go. I still have a bad feeling from changing the crank position sensor. It took me a week to put car back.

I have a spare intake so I will clean that one.

I was looking a thread with a vacuum diagram but it would not open. Does anyone have one?

Sparksman

New oil pumps alone are $300 or so, then plugs and wires ect... I can see $500 and taking you a few days for all that.

This shouldnt even be a days work, I could have off in 20 minutes lol. Thats why I say maybe a hour off, then a hour on for a novice. If you are swapping intakes replace the intake, TB, and IACV gaskets and injector rings/seals.



http://www.google.com/imgres?imgurl=...ed=0CCwQ9QEwAA

holmesnmanny

Do you know what egr plugs are ?

Sparksman

Lol hey man he did include "noob" in his thread title, I think this is the problem.


So OP, watch this video and he will show you how to fully clean your egr ports. I myself wouldnt do inside the car just because I wouldnt want shavings in my intake floating around and find their way into a cylinder.



Since you said you have a second manifold outside the car already I suggest drilling out those plugs, tap and thread the holes. Then buy some threaded screw plugs to screw in the holes. This will make it 100X's easier if you ever need to clean again. Also it being out of the car makes it easier on you, and makes sure you can get all of the metal shavings out before you put it back on.

You can buy replacement plugs since they are one time use, which is why our friend Holmesnmanny found it odd you stated you cleaned and reused them lol...

Or if you feel you can somehow clean the ports on the intake out of the car without drilling out the plugs. Either with some combination of compressed air and brake cleaner give that a try. But if it doesnt work you now know what needs to be done, and that means another time taking the intake off.

holmesnmanny

Normally when you're throwing a code the egr holes are full of carbon soot which makes the shaving sit on top of the soot which makes it easier to suck the shavings out with a vacuum cleaner. The egr soot itself isn't a big deal since carbon can more or less combust, but the shavings can not.

Also, if you put grease on the drill as you drill the hole to pop out the plugs with a slide hammer the grease tends to catch most of the shavings before they fall in.

The key however is to try not to drill through the plugs that way you don't have to worry about the shavings. You just drill 3/4 of the way through, pop out the plugs and then just spray the soot with carb cleaner.

The plugs that honda sells, however, are only 1/16 of an inch thick so the second time around you won't be able to not drill through those.

holmesnmanny

also he said "it"in singular form which leads me to believe hes talking solely about the valve

Sparksman

Nice to see Im not the only one on here late at night lol.

Yeah i heard the replacement plugs are hallow and not made of copper, never had to replace them on my intake. My 94' is obd1, and the EGR had been deleted when I bought it. Sorry to say I dont know the obd2 or emission related woes lol.

Honda should have just had made all the egr ports have a face plate like on the euro-r intake mani. The plug idea was pretty dumb on their part, a handful of screws could be undone in seconds.

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Thanks Sparksman for the Noob save. Also, thank you for the video.

I have not been able to do anything to the car due to bad weather. I was able to remove spare intake from head. I will hopefully get a price to have it cleaned professionally vs cans of combustion cleaners.

The EGR was cleaned twice with combustion cleaner.

Cleaning the manifold would be a good start before i start to change out parts.

My younger brother is more into hondas but away in college. He said I should buy an aftermarket manifold but I do not remember what the name is.

Sparksman

If you are staying obd2 no point in aftermarket parts. Will throw codes and you're computer will fight to keep engine parameters the same.

If you want a better intake a Euro-R manifold would be you're best option. It flows better, increases power, and still has EGR so you wont throw a code.

You can take the manifold in for a acid bath which would remove any and all carbon, paint, everything for cheap. Less work in the long run, and way less money then a new intake mani.

holmesnmanny

smh My money is on the fact that he didn't even watch the whole video. However, even if he ever did, this guy never even actually cleans the tiny chamber ports to begin with. He just cleans the main chamber holes. While it may somehow puncture the carbon in the tiny 1 millimeter port holes it may not do them all or even fully for that matter.

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[QUOTE=holmesnmanny;49380534]smh My money is on the fact that he didn't even watch the whole video. However, even if he ever did, this guy never even actually cleans the tiny chamber ports to begin with. He just cleans the main chamber holes. While it may somehow puncture the carbon in the tiny 1 millimeter port holes it may not do them all or even fully for that matter.[/QUOT]

i maybe a noob to preludes but not a noob to fixing car. Egr was cleaned, vacuumed and air blown. I am sending intake out to be acid dipped.

holmesnmanny

Is it really too much to ask for you to actually say you cleaned the egr ports ?

I mean really.

However, I supposed if you did, you would know what I'm talking about and wouldn't need to dip your intake in anything.

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I finally got a chance to clean ports. They were clogged badly. I vacuumed, scrapped, sprayed lots of throttle body cleaner and forced air into ports to blow out and dry up the cleaner. I cleared the codes then started car. Engine light came on showing misfire on cylinder 3 which was previously on cylinder 2. I have to diagnose that now.

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I drove prelude around the corner and light went off. I pulled in front of house and idled the car for a few away. Few second pasted and the light came back on. I am going to check the cylinder again for compression numbers.

Any other suggestions?