ali7up

I failed my emissions on a 95 accord lx, the reason was NOx was too high

25/25 NOx Allowed 945 Mines 1323
50/15 NOx Allowed 1045 Mines 1307

I have a magnaflow flow cat and magan headers

any ideas? i took it to a shop the guy said im sure its the cat converter? if that is the problem will it be ok if i get the magnaflow direct-fit 22636 cat instead of the honda oem. thanks

dEXstar

I had issues like this with my 94 Civic. After three years of this I just picked up a new Honda Cat and I passed with no problems. I now run the Magaflow and when it comes emissions time I put on the Honda Cat.

ali7up

yes i was thinking about the honda oem but its like 725 from the dealers and 500ish online

cctgene

Just a thought - Are you sure your EGR ports are not clogged?

raceACCORDingly

get a the carsound series cat from magnaflow that is smog compliant.

http://www.car-sound.com/

clean out egr

lost resort try a bottle of the CRC guarantee pass smog. stuff works.

ali7up

im going to clean the egr ports and retest if not then ill replace the cat from car-sound and see what happens

ali7up

ok i cleaned my egr ports, seafoam the crankcase oil, gas tank and replaced the cat with walked direct fit cat and the car failed even worse results:

25/25 NOx Allowed 945 test 1470
50/15 NOx Allowed 1045 test 1535

Eagleman

When you replaced the Cat, did you replace the O2 sensors??? If the cat failed, it was probably caused by the O2 sensors, The cat usually only fails when gas rich exhaust enters the converter and ruins the platinum inside. They usaully never go bad by themselves.

If you didn't it might ruin the new converter as well.

ali7up

i didnt replace the o2 sensor

Eagleman

Then your O2 sensor is bad. Replace it and you should pass emissions, barring no other problems.

ali7up

ok i will change it today but does it make a difference if i use oem or
Bosch

Eagleman

No it shouldn't, I used Bosch in my 98 Honda when I had to replace my Cat. Make sure that you don't have two O2 sensors. Hope this works for you.

ali7up

yea there is one one that goes into the header and also can this be caused by bad sparks plugs since some say after running seafoam you should replace the plugs

Eagleman

I'm sure it could add to the problem over time. But I would think for a spark plug to be not working or helping in the burning of all of the fuel before it heads to the Cat, you would notice a loss of power. It would sure make the O2 sensors work overtime. Since plugs are cheap(er) and easy to replace, I wouldn't take the chance. I don't know much about using seafoam. But for peace of mind you might want to change them anyway.

Targa250R

High oxides of nitrogen emissions have little to do with the converter. Had I seen this thread earlier, I'd have told you not to waste any money on that. Catalytic converters primarily affect hydrocarbons and carbon monoxide, rather than NOx.

High NOx emissions are caused by high combustion chamber temperatures (over 2500*F). High combustion temps are usually caused by a lean air:fuel ratio or malfunctioning EGR system. You mentioned that you cleaned the EGR ports (did you clean ALL of the ports in the manifold?), but it is possible that the valve isn't lifting enough. Try another EGR valve. It is possible but unlikely that the oxygen sensor is causing a lean condition as well.

Make sure that your distributor base timing is set correctly. Try retarding it slightly if state regulations allow. Make sure to use fuel with the least amount of ethanol in it.

Eagleman

Isn't it possible that the O2 sensor(s) is(are) malfunctioning and telling the computer to send a leaner fuel mixture to the combustion chamber? Thus causeing the higher burning temperature? Just a thought. But what you say does make sense and you are correct that he needs to make sure he cleaned all EGR ports in the manifold.

ali7up

yea i cleaned the egr ports completely, i did notice that after i replaced the car, seafoam and cleaned the egr ports, the engine light came on for code 9, after i drove the car for an hour it turned off.

fiveten

catalytic converters have nox beds in them they do reduce nox....what was your HC,CO,CO2,O2?

fiveten

when you cleaned the egr ports you removed the cover plate on top of the inake manifold used a screwdriver or drill bit to clean the carbon out of the egr ports (they go straight down into the intake manifold) and replace the port gasket?

ali7up

First test:

25/25 HC PPM Allowed 132 Test 7
50/15 HC PPM Allowed 136 Test 10

25/25 CO% Allowed 0.73 Test 0
50/15 CO% Allowed 0.76 Test 0.1

25/25 CO + CO2% Allowed Min 6.0 Test 15.2
50/15 CO + CO2% Allowed Min 6.0 Test 15.1

Second test:

25/25 HC PPM Allowed 132 Test 7
50/15 HC PPM Allowed 136 Test 1

25/25 CO% Allowed 0.73 Test 0.1
50/15 CO% Allowed 0.76 Test 0

25/25 CO + CO2% Allowed Min 6.8 Test 15.2
50/15 CO + CO2% Allowed Min 6.0 Test 15.2

another thing i noticed is when i replaced the cat and did all the cleaning that morning the engine light came on for code 9..CYG sensor and after about an hour it just turned of. I will try cleaning the egr again tonight

78CITYTURBO

Ali7up, how are you? Did you ever fix the problem? I'm having the same problem too. I changed the upper front and lower o2 sensors...oem honda o2 sensors, cleaned the egr and the egr ports, still get the check engine light. I have change the cat. nor the plugs and plug wires. I'm going to drive the car around for a while to see if the check engine light will go away before I change out the cat convertor.

ali7up

tell u the truth i drove he car all day today and the light did not come on i check and there were no codes either so im guessing its gone

Mrbigaznboi

hey so have u passed smog yet? what was the main problem? i failed smog recently because of the NOx and im not very good with cars.. i am in need of some hep =(