Hey guys i'm new here and if this has been posted already sorry. I just dont know how to search it properly. I just bought a 90 accord with 256k miles. Its a lot, but i got it cheap. Took it to smog and heres the results:

Visual -PASS Functional check - FAIL Emissions test (gross polluter)

15mph test
rpm 1729 %CO2 11.0 02 meas 3.9 HC (PPM) max83/ meas 142
CO (%) max 0.75/ meas 1.45 NO(PPM) max 559/ meas 3047

25Mph test
rpm 2702 %CO2 13.1 02 meas 1.9 HC (PPM) max65/ meas 70
CO (%) max 0.63/ meas 0.68 NO(PPM) max 516/ meas 1698


PLEASE TELL ME WHAT YOU GUYS THINK. THE GUY RECOMMENDED AN AFTERMARKET CAT.
THE CAR DOES CURRENTLY HAVE A SMALL EXHAUST LEAK ALSO.
NEW SPARK PLUGS??
OIL CHANGE???
LET ME KNOW GUYS. THANK YOU!

 

An exhaust leak can cause the air/fuel ratio to be messed up. The oxygen sensor will not detect the actual oxygen in the exhaust gases from the engine, because outside oxygen will enter the exhaust pipes.

Where is the exhaust leak?

 

Its hard to tell where the leak is, but i can def. hear it when idling and push the gas then let off. Its after the cat i'm pretty sure. You can hear it from the muffler tailpipe air is coming out somewhere. I found a place that can install the cat for 145. I really dont want to spend the money if i dont have to, but if i must than i must.

 

I would definitely give the car a tuneup. New spark plugs, distributor cap, and distributor rotor. Only use the NGK plugs ZFR5F-11 that you can get at any parts store. I typically suggest getting a distributor cap and rotor at the honda dealership or finding an online seller of Honda parts for the cap and rotor. You will probably spend ~$10-$15 more for the honda parts. These are maintenance items that can wear out, so it is worth eliminating them as the problem.

I would also check for engine codes. In the common DIY threads on top of the gen tech help forum, there is a link on how to check engine codes. If the check engine light turns on while driving, then a code should be stored on the ECU. I would check no matter what, just to eliminate a sensor as the problem.

Changing the oil and filter at the proper mileage is good idea. I doubt that it will change the emissions readings you have.

 

im just curious why the smog dude didnt say that about spark plugs etc. He was an older honest dude who i found good reviews online for. He inspected the report and circled some things saying "ya its gotta be your cat, id try that first". And considering he doesnt sell or install cats he wasnt trying to make a buck.
Also there is absolutely NO check engine light that is on. I'm thinkin to change the plugs anyways since i do see some oil leakage into the manifold area.

 

Where are you noticing an oil leak specifically?

The tuneup items could solve your problem. These are items that should be replaced after a recommended number of miles. My tuneup suggestion is to do work on the car that may be necessary. In the end, this could a catalytic converter problem.

 

Manifold gasket. I just did the plugs last night. one of them was really loose. Good thing i dont race around or else it might of shot out. The distributor looks pretty new actually. Sure it was changed with this many miles.
Only reason i'm stressing the CAT swap is b/c i'm BROKE! I bought this car thinking maybe put a hundred-200 in it and it'll do me good.
IF i have the dimensions to the CAT would putting a generic one work?
Or is that place charging me 140 installed not to shabby?

 

High NO concentration usually means clogged EGR ports on the intake manifold.

In the common DIY thread on top of this forum, there is a link to cleaning the EGR ports for a 90-93 accord. Also google T2T013.pdf. The first part shows the same procedure for cleaning the EGR ports. The slide hammer they use is to pull the plugs out of the manifold, if that makes sense.

I would try correcting these problems first before possibly wasting money on a new catalytic converter.

 

awesome....thanks bro

 

If you're certain the distributor was replaced, why don't you look inside the cap and check the rotor while you're at it? It's easy to do it, take off three bolts on the cap and you're done. Put them back on to put the cap back on.

When I ordered the OEM Honda cap and rotor I actually found them to be cheaper or around the same price as the Duralast (Wells Mfg.) cap and rotor they sell at AutoZone.

The Honda parts retailer I bought my OEM cap and rotor from also gives you the gasket that goes between the cap and the distributor housing if you buy the cap. I checked one website and they were charging a fortune for this gasket alone from a non-Honda OEM source. I have no idea why. So I personally agree with the OEM suggestion simply because you get a lot for such a good price and it's guaranteed to work with your distributor.

The only thing that might increase the price is shipping, AutoZone or another auto parts store near you doesn't charge shipping if the cap and rotor are in stock at your local store. I'm sure the Wells Mfg. cap and rotor are fine but I like to keep things OEM whenever possible.