First off, how long did you drive the car before the inspection? I know for the best results, you need to drive the car at a high steady speed to allow the temperature to get to its maximum level to burn as much fuel/air mixture as possible.
If your truck is not running good, then a carb rebuild may be in order. However, if the truck runs good, it sounds more like an emissions system problem. Here are a few things in the emissions system you can check. Check thermal expansion tank for deformities or cracks. Check charcoal canister for clogging and clean if necessary. Check all hoses for deterioration, damage, restriction or collapse and repair or replace as necessary. Also check hoses for tightness on fittings.
How the emissions system is supposed to work, is when the O2 sensor senses the fuel/mix is not burned completely, it opens the EGR valve to recycle some exhauast back theu the intake to reburn the mixture. The system trys to get the fuel burned enuff to where the catalytic converter can burn the remaining fuel and give us very low emissions out of the exhaust. The reason I asked about how long you drove the car before testing, is you want that catalytic converter to be up to temperature so it will do its job of burning the remaining fuel before it hits the test machine.
Now, if your truck runs poorly, or you cannot find anything wrong with your emissions, then it may be time to take the truck to a mechanic that you trust.
Wednesday, August 23rd, 2006 AT 3:11 PM