ajsuper7

hello, i already read in the faq about emmissions and i have a few specific questions. my car is a 91 vert automatic with a bonez single cat as the only mod also only 30,000 miles on a rebuild. I passed emmissions last year with no troubles but this year im having issues. my HC readings are 128 ppm at 25mph which fails by exactly 1ppm but my low speed shows the HCs at 247ppm and 132 ppm is the max for houston. all other emmissions were well below the max allowed (CO, Co2, and NOx). im not sure what the cure is, the mechanic said it looks like its running too rich at low speeds. i changed the plugs but im not sure what else to do. in the faq it recomended setting the variable resistor to lean but im not sure what that is or how to do that. when i go back i plan on really running the car on the freeway and maybe throwing a little bit of alcohol in the tank but thats all i can think of, the car is maintained well and runs great. i suppose the O2 sensor might need to be replaced but im not too good with emmissions related components, i just like to remove them.

HAILERS

A new 02 sensor might help above idle but won't help at idle. The 02 sensor is out of the loop at idle.

Series five have no variable resistor to adjust.

Checkout the ACV per the online fsm. A quick check would be to get the engine fully warmed up. Pull the large hose off the bottom of the ACV. Feel for air coming out of the port where that large hose connected. A slight bypass of air at idle is ok. Then rev the engine to above 3800 rpm. When you hit that rpm a massive amout of air should expell from where that large hose connected. Now go back to idle. The massive amount of air should stop. There are more detailed checks, but that should give you a clue if it's working or not.

The high HC might indicate a water thermo sensor plug has come off. It's on the back of the water pump housing.

Make sure the split air pipe is connected to your catalytic converter.

New plugs never hurt. I always put new ones in before getting inspected.

Make sure the timing is spot on.

If you had a safc I'd suggest taking fuel out at idle to three grand.

That's about all. Yeah, your way rich for?????????????reasonl