Failed Emissions, Help!

[OtisSpunkmiester]

Installed a cat today on my 93 gs, took it to emmissions and it failed.
Readings were

HC- .5963 PASS
CO- .1273 PASS
CO2- 311.0045
NOx 6.0664 FAIL

It also says "High NOx reading are the result of high combustion temp. and/or high combustion pressures."
Probably a stupid question, but could i have installed it backwards?

Please help ASAP!!!!!!!! My temps expire today... if i cant get it figured out today i cant drive.

 

[11Banger]

Offer the guy 75 bucks under the table... with the time frame you're looking at thats about all you can do

 

[OtisSpunkmiester]

other suggestions please?

 

[11Banger]

other suggestions please?

Im new to DSM's

but using iso heat in the tank and retarding the timing helped me pass California smog test in my old 240, so idk

 

[300hpbound]

There's the possibility of it being backwards, but I wouldn't think so otherwise your hydrocarbons and CO readings would fail too.

Most of the time with high NOx readings, it's carbon buildup in the engine. While your car's running, those carbon deposits become extremely hot and give you the high NOx readings. Unfortunately there's no real quick fix to this. Grab a can of BG 44K and toss that in your gas tank and drive 50-100 miles and go for emissions again. Also check your EVAP system just in case. By check the system, I mean just make sure there's no vacuum hoses loose or disconnected

 

[OtisSpunkmiester]

Kind of solved it.. So i put the cat on and it fails emissions because of high NOx so i check my entire EVAP system and stuff and i cant solve it. So that afternoon i went to the motor vehicle place and begged for an extension on my plates and they gave me another 30 days! im so glad i talked to the guy that first gave me my temps. So now i have to make the four hour drive sometime to get it registered where i dont have to have emissions! It was an interesting saturday...

 

[Lou98GSX]

car might be running to lean make sure you don't have any vaccume leaks check your intake gasket and timing to .

 

[OtisSpunkmiester]

How can i check my timing? i couldnt find it at all in a repair manual or anything.