here in pima county (Tucson) az. we have to pass emissions to get tags. they test your air system, catalytic converter, and gas cap. my gas caps always pass, i'm cat exempt, and all the eqipment is there. thats called the equipment inspection, and i pass that part. my trouble comes from the emmission test. the loaded standard for hydrocarbons is 300 - for carbon monoxide is 3.00. the idle standard for hydrocarbons is 300 - for carbon monoxide is 4.00. last year the truck barely passed with results of hydrocarbon loaded 52 - carbon monoxide loaded 2.99 and hydrocarbon idle 126 - carbon monoxide idle 2.45. this year it won't pass. the loaded readings have went up and the idle readings have went down. this years first test readings were loaded hc:108, loaded co: 5.50 and idle hc: 113 and co: 4.00. so i though it was a simple carb adjust. and scewed the mix screws way out and retested. but it only brough it down to loaded hc:87 - co:4.88 and idle hc:70 - co .61, which still won't pass. so i went to work. set the timing, pulled the carb because of leaky gaskets and replaced the power valve (supprised to find it was locked up) founed vacuum ports that were blocked solid with carbon, so i cleaned them out, checked the egr(good). replaced almost every vacuum line on it, some were just old and soft, a couple were sucked flat, and some weren't there. but anyway, can you guys think of anything else i should do before retesting? i don't want pay $60 to $100 to have this truck put on an analizer(?) just to find out that it will pass and then pay the almost $13.00 fee for the test. of course i'd rather pay just the $13.00. you guys who don't have to do this crap are so lucky. i'd like to just tear all this stuff off my motor, it look like a damm plate of sketty anyway. thanks for any help guys.

 

Where I live in Texas we have emission testing too. What work for use is move away from your std oils and move to SYN. Syn do not produce the hydrocarbon emission as std oil. We most always do it on a fresh oil change. I use Amsoil, Valvoline would be a good choice to. We also run some RXP gas additive, 1 oz/10gal gas. This needs to have a min of 100 miles on it before testing. This works for me. I pass this year without doing an oil change, but I drive less than 3000/yr. I had a cat on mine that was replaced a year ago.

O2 sensors can also make a big difference. I had to replace one on one car before it passed.

 

You would be surprised how a new set of plugs will help it run. Also while it's idling, take your fingers and push up on the egr valve diaphragm. The engine should run rough and maybe stall out. If it doesn't then the passage ways in it may be clogged with carbon too. And as you rev the engine after it's warmed up, you should be able to see the egr valve start to rise up and open.

 

thanks you guys.....oil change and plugs comin up. i'm going to have to look in the book to learn about (where ) 02 sensors, if any. i'm not familar with them. Franklin2.......while i had the EGR off, i put a new piece of line to it and sucked on it and it held air. carb base plate was where i found the carbon build up, of course i cleaned it out. so even if the EGR maintains that suction/vacuum it could still be bad because of carbon? man, thats something those autozone guys never tell ya about.