So, when I had the shop install my headers about 350-400 miles ago, I had them put a 160 stat in (I know, I know, bad idea). Well anyway, I replaced it with a 180 this morning because I could see it was simply running too cold...on the highway, the temp needle (which isn't that accurate anyway) was barely moving off of 100...it was obviously way colder than before.

I ran it through for a sticker (I doubt the shop heated it up much like I asked them to), and it blew twice the legal HC limit, and close to the NOx limit. Could the Hypertech chip be screwing it that much? It didn't last year...it passed ok with it in the car. Could running it too cold for that period of time have hurt the cat, and thrown some crap on it? I just put the headers on, but 50 state legal TES TPI headers can't have hurt emissions...right?

The plan right now is to remove the chip, run some Guaranteed to Pass through it (it worked wonders 2 years ago when NOx was too high because the EGR solenoid was dead...it cleaned the cat up good back then), get it hot and have them test it. With my 200 temp Hypertech fan switch, it will be harder to get it hot than before, but at least a good run around for a little while will heat the cat up enough.

Any other ideas? The Magnaflow cat probably has less than 15k miles on it...

 

park at the station and just keep it at 3.5-4k while listening to the music until the t-stat says 210 and the fan kicks on... you won't get much cooling standing still, if you're just looking to kick up the heat to pass

 

I think this means I need to remove my Hypertech fan switch then, because it is set to turn on at 200.

Now here is something interesting...and something I was afraid of when I put the 180 in...now the fans never turn off. The engine wants to run warmer, but the fan is keeping it colder...it never did this with the 160 in. So now it runs a constant 180-185...I have a problem

Time for the OEM fan switch to be put back in? I put in the Hypertech when everything was changed because I wanted to keep down on the hot air being sucked in by the open element!!

 

rig it so that it passes, then put it back like it was. you only have to do it once a year

 

just let it idle in the lot untill they go out to get it, tell them the keys are in the car.

Also, maybe some denatured alcohol in the tank. I hear a good ratio is: run the tank as near empty as possible, put 1 gal of denatured alc. followed by 3 gallons of premium at the pump.

 

http://www.rodneydickman.com/retail_new.html

Here u can find the on/off 210/200° fan switch. Wich addet to a 180° thermostat will probably give u the best functional performance with tbi running in rather hot conditions.

 

When i failed at about the same as you did all I did to make the car pass is retard the timing (because i was advanced 6 degrees), to -2 to -4 degrees. Passed with less than half of the values I would need to fail. I was running regular gas, and had the car nice and warm by the start of the test.