chilix

I took it to get checked out and everything looked great except for the Nitrous Oxide (NO) which went over...what could cause that problem? Could it be the catalytic converter?

I need help!!!

Jakerx

it most probably is a catalytic converter. cheap universal replacements can be found unless you want to go for oem replacement.

chilix

the problem is that I don't want to replace the catalyic converter and find that it might be something in the engine raising combustion temperatures for example...

are there any test to figure it out?

Jakerx

on my friend's legend he had the same problem. so we gave it a complete tune-up and some thicker oil, and it passed with flying colors. don't know if the same will apply to you. good luck.

chilix

i'm already runny 20W-50 oil in my car...i haven't done a tune up yet...it is just everything else passed like the car was new except the NO which failed the car...the car passed last time same way, very clean like it was new just it didn't fail that time...thanks though, i'll see what i can do

Danno

How far over the limit is it? You can use the FQS switch on the DME to increase fuel a little bit and retard the spark, which should help lower NOx a bit. But depending upon how far over you are, it may not be enough. Most likely it's the car.

chilix

the allowable is 1208 ppm in the state of georgia for my car, i had 1302 ppm

rich k

Forgive me for being criminal or shady in any way but I thought everyone knew a guy who could get his car through emisions. I pay a guy $100 and I get a sticker to install myself. It is technicly illegal

Danno

"the allowable is 1208 ppm in the state of georgia for my car, i had 1302 ppm"

That's darn close! How much leaway do you have with HC & CO? You can use the FQS switch to add 6% fuel and a 3 degree ignition retard. This will increase HC and CO some, but will lower your NOx; most likely enough to pass.

Yabo

I'm going to say it's not the cat, although a new cat would probably lower the number some. When my cat was gone, the Nox and the co i believe? were both wayyyy high and replacing the cat brought it down to like 40th's of the numbers...

Mike1982

My car didn't pass by over 1,000 last summer, due to the cat, but I did do the plugs, wires, cap and rotor, oil and filter, plus new air filter before I went back and it did drop quite a bit. I think the first time I didn't pass by about 1,300, on the second time it was more like 950 or so. So it did drop down but then again I did need new plugs at the time along with the air filter. I talked to a guy there that said if that is that high, usually that is the problem but I ended up getting a waiver for the car due to the wastegate I just put in.

chilix

I'm going to check the Oxygen sensors...maybe one has a broken wire or something...

A mechanic in Roswell, GA was real confused by my number at how all the others were so low yet the NO was 96 ppm over, if I cannot get it solve I'm going to let them test my catalytic converter

the fail was only in the 25mph range, the NO passed in the 15mph range by about 90 ppm
last july my car passed everything like it were new...

sharkwing1

you may want to try running some stuff called sea foam through your car, it worked for my honda...you can put 1/3 of it in your gas, and 1/3 through your pcv valve and its only 5 bucks at NAPA

nine-44

Check to see if the O2 is sending a signal, usually if they fail they go dead. The voltage should be like .1-1V. My dad's car failed also, the O2 signal was .061v max. I replaced the O2 and it passed beutifully a few days after failing . That was all I did. IIRC the NO was upand the others barely passed. Good Luck

Danno

"A mechanic in Roswell, GA was real confused by my number at how all the others were so low yet the NO was 96 ppm over, if I cannot get it solve I'm going to let them test my catalytic converter"

That's a sure sign of a lean mixture. There's a crisscross function of low HC/CO giving high NOx and vice-versa with high HC/CO giving low NOx. So you want to juggle all the emissions in the middle somewhere. Adjusting your fuel-mixtures to be a little richer to get higher HC/CO, but still below the limit, will definitely drop your NOx into the passing zone.