Looking to buy 97 prelude but has aircare problems

[JDMes]

Hey everyone i've been looking at a 97 lude to buy, but I just checked the aircare history and its pretty bad. I'm wondering if this could be the cat or worse problems. I'm going to check it out later today and would like to run this by the pro's before I go.



What do you think? the owner said that he had newer motor and tranny installed in the spring. If it seems like a cat or minor tune up thats no problem but I dont want to be swapping engines etc. Thanks for the help !

[PuYang]

Thats an automatic i think? judging from the VIN number.

Have you done research into 5th gen preludes? The automatic transmissions are a ticking time bomb. Its highly recommended to get a 5speed manual prelude. (although you say the owner just put in a new transmission. which means it already had the problem, and was fixed?).

and what was the reason the owner put in a new motor? usually, cars pass aircare easily as long as its "close to stock", and had a recent tuneup, there should be very little reason to fail aircare.

sorry, Im noob when it comes to looking at those charts, so i cant give specific details on what to fix.

I drive a 99 prelude, only has a cold air intake. stock cat etc. had a tune up, and then past aircare easily.

[JDMes]

Apparently it has an aftermarket intake and exhaust (maybe that's why its failing?), Owner says he has receipts for new motor and tranny. Its priced in my budget that is the reason I'm interested, but if its going to cost me a bunch in repairs its not worth it.

[Puck Luck]

my thoughts are...fix the nox and that should fix the hc. from my experience, looks like EGR problem. Likely plugged ports.
Thats if everythings stock. If there's alot of mods, then all bets are off

[doma]

DO NOT BUY AN AUTO PRELUDE.

you have been warned.

There is a reason he has a new tranny.

[european]

Do the following. Install new catalytic converter, OEM cat preferably. If CEL is on check the code as it might be EGR, if so, fix EGR by cleaning ports and cleaning the EGR unit by spraying some carbon cleaner. If you need to you can change the plugs and wires as it might help. After you install the new OEM cat do an Italian tune up then go straight to AirCare, you should pass.

Yes, its an automatic Prelude as the VIN has a 2 after BB6. Unless it has been 5speed swapped already.

Lastly, join VancouverPreludeClub.net If you haven't already done so.

I have a aftermarket intake and full Mugen exhaust but recently needed a new catalytic converter in order to pass AirCare. Honda Preludes equipped with a H22A4 rely heavily on the cat to clean up all the junk. I purchased a OEM replacement cat which is not OEM Honda and my readings were a bit better then before with my JDM cat. However, I did an Italian tune up for about an hour before going to the AirCare center.

My readings before and after:





Hope this helps
Cheers
Mike

[JDMes]

Owner installed new cat and it passed with flying colors, test drove it and it ran mint. Receipts for motor with 157km, full rebuild on tranny, and lots more. Got an awesome deal. Going to buy after work!

[european]

Awesome! Congrats. Post some photos. VPC is gonna have a little meet soon. You should come out.

[doma]

congrats on the purchase....but your gonna be kicking urself for buying and auto 5th gen.

[Puck Luck]

Was this a genuine Honda converter? They retail for well over a grand.

Even though it passed with a new converter, you should still check to see if the egr ports are plugged. It's easy enough and can do a quick test in seconds.
It's quite possible the new converter is only masking the high emissions the engine is putting out. And if it is high, it can damage the converter. Especially being NOx, it means the combustion temps are too hot.

A healthy prelude engine (before the converter) should be putting out around .5% CO and 50-80 ppm HC. Its required as a feed gas to light off the converter.(not sure what that would translate to in the g/km scale). I can't remember what NOx should be but i suspect it might be low enough before the converter to pass, cause of the egr system.

I'm suggesting this because i know this is a common problem on this generation prelude and earlier accords and is easy to test. If they are plugged, they have to be drilled out to be cleaned

[JDMes]

The egr has been cleaned and it passed well below the average passing reading. I'll take some photos later today and post em but wont be going to any meets (not really a meet kinda guy lol)