Hello Honda-Tech forums. I know I made the same thread on another forum but I realized afterwords that this forum here is more suitable for this discussion

Hello Honda-Tech forums. I am simply making this thread to document what had happened and what is the current state of progress on parts I have orderd to combat my cars previous failure with smog.

My vehicle is a 1999 Honda accord LX 2 door C.A.R.B certified Ultra low emission Vehicle (or ULEV for short)

I have had this issue for a long time now but finally have come up with the funds in attempt to combat the continuous on an off of my check engine light. The issue starts with the car failing smog check. The report reads a fault code and Carbon monoxide levels (CO) Being too high. Which is odd because 2 years ago the readings where different. This is usually in relation to the air fuel mixture which in turn is usually caused by reading from the O2 sensor in the catalytic converter that talks to the ECU. the 02 sensor in the front is good and pretty much new (OE nippon denso) so that is clearly not the issue.

Now here is the tricky part. The only part that is listed under that engine number for ULEV is ONLY sold by honda. The part number is
18160-PAA-L20

this is designated to the engine number found underneath the hood of my car (a small white square of a sticker that explains emissions)
XHNXR0130AAA

HOWEVER. There is another converter made by magnaflow that is very likely to be almost identical in terms of it's workings (yes it is California Approved)


I have already placed an order of this on Amazon and there is a comment written by a user who has the same exact ULEV vehicle. They said the light did not go off after that. Then not only that, they gave an update 2 years later and said that it is still working with no issues at all.

Another thing that I must note is that the current catalytic converter I have on, to my own shock (because I originally expected it to be the one that was installed out of the factory) is missing a heat shield that I never even noticed was supposed to be on there in the first place AND is welded straight to the resonator (pipe that leads to the muffler, Work was most likely done by a muffler shop from the original owner). I ordered 2 brand new heat shield parts (2 total in plastic honda genuine parts packaging) off of ebay for about 34 bucks. which is good because it's 32 each at the dealer, and as an update they have arrived here already which is far sooner than I expected

I also bought , and is fitted towards the coupe model. The sedan numbering is different but walker makes both for the two different body styles.

While I was at it I also ordered new rubber mounts (made by bosal)
and a new Denso 02 sensor that is factory spec as well as a new gasket for the rear part of the resonator that connects to the muffler. I got all of these from Rock auto.com.
The only thing I have left to hit is finding the right bolts. The only odd one seems to be the ones for the heat cover. It is an Itawa 6x10 fanged bolt from what it looks like on the diagram from the dealer. The other bolts I do believe I can get from any hardware store (forged bolts preferably)

One last thing to note is that I ordered a Bluetooth Mini OBDII scanner off of Newegg and bought the torque pro metering app for my android phone. I am very excited to see all of the systems working real time on my phone.

If anyone knows what the sizes are for the exhaust bolts that join the flanges please let me know ,Mike

 

If you are in Calif, then you have the 5 gas test, post up the results.
New parts fail too. Just because the CEL has not been set does not mean the O2 is becoming inefficient.
If the CEL light is on there is a problem, something is not kosher. Pull the code and post it.
It may not be ULEV spec or there may have been other hacking done to the vehicle. The ULEV catalyst is expensive due to the higher amounts of precious metals inside the case for a cleaner emissions output. Albeit the ULEV has stricter/tighter parameters that need to be seen/met by the PCM, and when not sets the CEL.

 

Give me some time i have to get them all together. IT did pass smog with flying colors though. The Co emissions Drastically Dropped! From i think like .75 to .03. Engine noticably has much more pickup now and gets far better gass milage than it did before. I drove all the way from brentwood to san jose then back and used a little more than a quarter of a tank going about 81 to 83 on the freeway. Plus vasco which is a steep road on some parts.

I got the P0420 code last time which is identifying that the catalyst isn't doing it's job, The downflow O2 sensor wasn't giving steady readings when the engine was fully warmed up. Also i should take a picture of the old converter to show you how terrible of a job the muffler shop did on it with the previous owner. I made sure everything was direct fit since these cars are incredibly picky with emissions.

Damn right it is. For recycling it i get 230 bucks! which gives a big deduction for 380 dollar magnaflow i bought. The rear exhaust pipe/resonator is a piece of crap though. It has a tiny leak in the resonator. I think i'll just replace it with a factory stainless steel one later on. believe it or not it's made by sankei. honda has always had reputation choosing good materials for the parts they put in their cars. Don't know about the ones being made today though.