Smog Still breakin my balls

[z32Odoom]

Ok, so i'm about ready to kill my mechanic,
I've replaced my egr valve, Thermostat, Catalytic converters,
Still failing in the 700's and i guess your under 500 is passing.
Hes telling me now that i need to replace the spark plugs, i don't see that making that big of a difference, but i'm going to do it anyways,
Is there anything else that i'm missing here?

[BigTDogg (MA)]

Ok, so i'm about ready to kill my mechanic,
I've replaced my egr valve, Thermostat, Catalytic converters,
Still failing in the 700's and i guess your under 500 is passing.
Hes telling me now that i need to replace the spark plugs, i don't see that making that big of a difference, but i'm going to do it anyways,
Is there anything else that i'm missing here?

Try retarding the timing to 13°BTDC. IIRC, that's a trick some use to pass.

[a.p.barron]

You mind posting all the numbers?

[z32Odoom]

the only thing its failing on now is nox levels, where as before it was failing on literally everything,

Nox 15mph = 791 (max 484)
CO%=.03 (.34 Max)
HC= 8 (max 59)

btw i'm in california also, soooo, s***.

Guy is tellin me i need to replace the spark plugs because the guy i bought it from put the bosch platinum 4 prong ones in it. I just don't see that making a difference of 300.

Any help is appreciated.

[a.p.barron]

Hmmm, I don't see how it could be your spark plugs. If your spark plugs were shot, wouldn't you be getting high HC levels?

Anyway, check your timing. If it's too advanced, that's what could be getting you high NOx levels.

A trick that I like to use for passing smog is to first Seafoam my car to clean up the valves a bit. After that, I'll run the car down to almost an empty tank of gas, and then put 1 or 2 bottles of ISO Heet in the tank. After that, I fill it up to 1/4 full, and then I take it for a nice trip to warm it up right before I get it smogged. Just make sure as soon as you're done you fill your tank up all the way.

BTW, I'm also in CA. Good luck!

-Alex-

[z32Odoom]

ya i think i'll try that.

But in for the time i'm going to let the guy sweat his thermostat, he thinks he could have f*** it up installing it, so i'm going to let him tear it all apart again, replace it with a Nismo one, and put it all together again, once it fails again i'll try the sea foam. There is a whole bunch of carbon build up in the throttle bodies he says, so i'm thinking the seafoam could do the trick.

[z32Odoom]

oh and btw i just had the timing belt done too, so i doubt its the timing. But i can check that too

[a.p.barron]

The thermostat could definitely be your problem. If your engine is running too hot, that could cause high NOx levels.

[z32Odoom]

in all honesty i don't think they messed up installing the thermostat, the mechanic shouldn't be aloud to diagnose smog problems, but i don't think he put the thermostat in upside down, which is what he thinks could have happened, there is carbon build up throughout the engine, i think thats the problem, i went to a different guy today and he says in older cars the carbon build up on the piston head heats up to extreme temperatures sometimes causing nox to be produced, the guy seemed like a really intelligent guy, unlike the mechanic who is working on my car now. But we will see how it plays out.