You will ALWAYS fail if the engine has not been run for several miles. We run the tread mill here in GA also and never had a problem passing the sniffer. Just before they started with the rollers I went for my fail because I was missing my cats. I passed the sniffer with no cats at all. Tells you how much smog controls are BS! Dumb ass didn't look till after he had started printing it out and was disconnecting the machine and noticed the CATALIST sticker on the core suport. He let me slide caus a it passed and I told him I was expecting the fail because I wanted to make sure if I failed after thecats were installed I could get an exempt. Here if you show improvment they will give you a sticker if you show you spend a couple hundered bucks.
I don't know why they said they would have trouble with the big tires. Didn't have any problems with my 32's till the truck went for second and darn near jumped off the rollers
It shifts real hard LOL. It passed fine with those nice shinny new cats. Now my 75 is full time and I had to argu with them big time that they could not put it on rollers because it would drive off. It got down to me grabbing their jack and lifting the rear wheels and moving the truck with the reas off the gound. Then they had to call the smog nazi hedquarters on what to do LOL. They did a static test (no rollers). It put out less emmisions then my 87 4 cyl ford that did pass. 75 did not have cats from the factory and the only emmissions on the truck is a PCV.
ITS ALL A SCAM! a vehicle that is propperly tunned does not produce any un acceptable emissions.